How to make captcha/recaptcha in OpenCart 1.5.x registration form?

Question

reCAPTCHA

Good afternoon, please tell me how to install recaptcha on the registration page. Opencart version 1.5.5.1. Very tired of bots that hit the registration. I am very grateful for any help.
Page code

<?php echo $header; ?>
<?php if ($error_warning) { ?>
<div class="warning"><?php echo $error_warning; ?></div>
<?php } ?>
<!--<?php echo $column_left; ?><?php echo $column_right; ?>//-->
<div id="content"><?php echo $content_top; ?>
  <div class="breadcrumb">
    <?php foreach ($breadcrumbs as $breadcrumb) { ?>
    <?php echo $breadcrumb['separator']; ?><a href="<?php echo $breadcrumb['href']; ?>"><?php echo $breadcrumb['text']; ?></a>
    <?php } ?>
  </div>
  <h1><?php echo $heading_title; ?></h1>
  <div id="create-account">
    <p><?php echo $text_account_already; ?></p>
    <form action="<?php echo $action; ?>" method="post" enctype="multipart/form-data">
      <h2><?php echo $text_your_details; ?></h2>
      <div class="content">
        <table class="form">
          <tr>
            <td><span class="required">*</span> <?php echo $entry_firstname; ?></td>
            <td>
              <input type="text" name="firstname" value="<?php echo $firstname; ?>" />
              <?php if ($error_firstname) { ?>
              <span class="error"><?php echo $error_firstname; ?></span>
              <?php } ?>
            </td>
          </tr>
          <tr>
            <td><?php echo $entry_lastname; ?></td>
            <td>
              <input type="text" name="lastname" value="<?php echo $lastname; ?>" />
              <?php if ($error_lastname) { ?>
              <span class="error"><?php echo $error_lastname; ?></span>
              <?php } ?>
            </td>
          </tr>
          <tr>
            <td><span class="required">*</span> <?php echo $entry_email; ?></td>
            <td>
              <input type="text" name="email" value="<?php echo $email; ?>" />
              <?php if ($error_email) { ?>
              <span class="error"><?php echo $error_email; ?></span>
              <?php } ?>
            </td>
          </tr>
          <tr>
            <td><span class="required">*</span> <?php echo $entry_telephone; ?></td>
            <td>
              <input type="text" name="telephone" value="<?php echo $telephone; ?>" />
              <?php if ($error_telephone) { ?>
              <span class="error"><?php echo $error_telephone; ?></span>
              <?php } ?>
            </td>
          </tr>
          <tr>
            <td><?php echo $entry_company; ?></td>
            <td><input type="text" name="company" value="<?php echo $company; ?>" /></td>
          </tr>
        </table>
      </div>
      <h2><?php echo $text_your_address; ?></h2>
      <div class="content">
        <table class="form">
          <tr>
            <td><?php echo $entry_address_1; ?></td>
            <td>
              <input type="text" name="address_1" value="<?php echo $address_1; ?>" />
              <?php if ($error_address_1) { ?>
              <span class="error"><?php echo $error_address_1; ?></span>
              <?php } ?>
            </td>
          </tr>
          <tr>
            <td><?php echo $entry_city; ?></td>
            <td>
              <input type="text" name="city" value="<?php echo $city; ?>" />
              <?php if ($error_city) { ?>
              <span class="error"><?php echo $error_city; ?></span>
              <?php } ?>
            </td>
          </tr>
          <tr>
            <td><?php echo $entry_postcode; ?></td>
            <td>
              <input type="text" name="postcode" value="<?php echo $postcode; ?>" />
              <?php if ($error_postcode) { ?>
              <span class="error"><?php echo $error_postcode; ?></span>
              <?php } ?>
            </td>
          </tr>
          <tr>
            <td><?php echo $entry_zone; ?></td>
            <td>
              <select name="zone_id">
                <option value="0"><?php echo $text_select; ?></option>
                <?php foreach ($zones as $zone) { ?>
                <?php if ($zone['zone_id'] == $zone_id) { ?>
                <option value="<?php echo $zone['zone_id']; ?>" selected="selected"><?php echo $zone['name']; ?></option>
                <?php } else { ?>
                <option value="<?php echo $zone['zone_id']; ?>"><?php echo $zone['name']; ?></option>
                <?php }
                } ?>
              </select>
            </td>
          </tr>
          <tr>
            <td><?php echo $entry_country; ?></td>
            <td>
              <select name="country_id">
                <option value=""><?php echo $text_select; ?></option>
                <?php foreach ($countries as $country) { ?>
                <?php if ($country['country_id'] == $country_id) { ?>
                <option value="<?php echo $country['country_id']; ?>" data-iso2="<?php echo $country['iso_code_2']; ?>" selected="selected"><?php echo $country['name']; ?></option>
                <?php } else { ?>
                <option value="<?php echo $country['country_id']; ?>" data-iso2="<?php echo $country['iso_code_2']; ?>"><?php echo $country['name']; ?></option>
                <?php } ?>
                <?php } ?>
              </select>
            </td>
          </tr>
        </table>
      </div>
      <h2><?php echo $text_your_password; ?></h2>
      <div class="content">
        <table class="form">
          <tr>
            <td><span class="required">*</span> <?php echo $entry_password; ?></td>
            <td>
              <input type="password" name="password" value="<?php echo $password; ?>" />
              <?php if ($error_password) { ?>
              <span class="error"><?php echo $error_password; ?></span>
              <?php } ?>
            </td>
          </tr>
          <tr>
            <td><span class="required">*</span> <?php echo $entry_confirm; ?></td>
            <td>
              <input type="password" name="confirm" value="<?php echo $confirm; ?>" />
              <?php if ($error_confirm) { ?>
              <span class="error"><?php echo $error_confirm; ?></span>
              <?php } ?>
            </td>
          </tr>
        </table>
      </div>
      <h2><?php echo $text_newsletter; ?></h2>
      <div class="content">
        <table class="form">
          <tr>
            <td><?php echo $entry_newsletter; ?></td>
            <td>
              <input type="radio" name="newsletter" value="1" checked="checked" />
              <?php echo $text_yes; ?>
              <input type="radio" name="newsletter" value="0" />
              <?php echo $text_no; ?>
            </td>
          </tr>
        </table>
      </div>
      <?php if ($text_agree) { ?>
      <div class="buttons">
        <div class="left">
          <input type="checkbox" name="agree" value="1" /> <?php echo $text_agree; ?>
          <?php if ($error_agree) { ?>
          <span class="error"><?php echo $error_agree; ?></span><br />
          <?php } else { ?>
          <br /><br />
          <?php } ?>
          <input type="submit" value="<?php echo $button_continue; ?>" class="button" />
        </div>
      </div>
      <?php } else { ?>
      <div class="buttons">
        <div class="left">
          <input type="submit" value="<?php echo $button_continue; ?>" class="button" />
        </div>
      </div>
      <?php } ?>
    </form>
  </div>
<?php echo $content_bottom; ?>
</div>
<script type="text/javascript"><!--
var current_zone_id = '<?php echo $zone_id; ?>';
$('select[name=\'country_id\']').bind('change', function() {
  $.ajax({
    url: 'index.php?route=account/address/country&country_id=' + this.value,
    dataType: 'json',
    beforeSend: function() {
      $('select[name=\'country_id\']').after('<span class="wait">&nbsp;<img src="catalog/view/theme/default/image/loading.gif" alt="" /></span>');
    },		
    complete: function() {
      $('.wait').remove();
    },			
    success: function(json) {
      html = '<option value=""><?php echo $text_select; ?></option>';
      
      if (json != '' && json['zone'] != '') {
        for (i = 0; i < json['zone'].length; i++) {
          html += '<option value="' + json['zone'][i]['zone_id'] + '"';
          
          if (json['zone'][i]['zone_id'] == current_zone_id) {
            html += ' selected="selected"';
          }
  
          html += '>' + json['zone'][i]['name'] + '</option>';
        }
      } else {
        html += '<option value="0" selected="selected"><?php echo $text_none; ?></option>';
      }
      
      $('select[name=\'zone_id\']').html(html);
    },
    error: function(xhr, ajaxOptions, thrownError) {
      alert(thrownError + "\r\n" + xhr.statusText + "\r\n" + xhr.responseText);
    }
  });
});

$(document).ready(function() {
  $('.colorbox').colorbox({
    width: 640,
    height: 480
  });
});
//$('select[name=\'country_id\']').trigger('change');
//--></script> 
<?php echo $footer; ?>

Answer 1

https://developers.google.com/recaptcha/intro - here is the documentation,
and there is just a search in Google, for a start it would be nice to use it, because it's all been decided and explained