Sending to modx revo via ajaxform not working?

Question

PHP

Form submission not working. There are no error or success messages. Although everything seems to be connected correctly. All plugins installed namely Formit and AjaxForm. Please help me in modx I don't understand well. The standard one works, but mine doesn't.
Chunk code where is the tpl.AjaxForm form

<form action="" method = "POST" class="ajax_form af_example">
  <div class="contact_form">
    <div class="contact_form_item">
      <input type="text" class="contact_input" placeholder="Your name*" name="name">
      <input type="text" class="contact_input" placeholder="Your e-mail*" name="email">
      <input type="text" class="contact_input" placeholder="subject" name="subject">
    </div>
    <textarea rows="9" cols="64" class="contact_textarea" name = "message" placeholder="Your message *"></textarea>
  </div>
  <input type="button" class="contact_input_buttom" name="send" value="Send Message">
  
  
    
</form>

Ajaxform code

<div class="contact">
  <div class="container">
    <div class="contact_image"></div>
    <div class="contact_text">
      <div class="contact_title_text">Contact Us</div>
      <div class="contact_smail_text">Proin iaculis purus consequat sem cure</div>
    </div>
    
  </div>
</div>

Letter template code

<h3>Сообщение</h3>
<p>С Сайта: MODX Revolution</p>
<p>От кого: </p>
<p>E-mail: </p>
<p>Телефон: </p>
<p>Сообщение: </p>

Answer 1

...
    private static function ClassOption () {
        static $instance;
        if (!$instance) {
            $instance = new SearchOption();
        }
        return $instance;
    }
    ...

What you want to do is called Singleton

Answer 2

What the hell is this?
and here it is
k.m.k. need to fix

<input type="submit" class="contact_input_buttom" name="send" value="Send Message">