How to change the order form in Opencart 2.3 (phone number input field)?

Question

JavaScript

Hello! By default, in Opencart , the form for entering a phone number, when you click on the field, displays this window

, and then if you click on this window that has fallen out, we get this:

I tried to remove the name="telefone" attribute, and in the checkout.php file I assigned entry_telephone (the one that goes to the attribute of the tag) - instead of the word "Phone" the characters are: '+7 (___) ___-__-__' that is got this code:placeholder="<?php echo $entry_telephone; ?>"

<input type="text" value="<?php echo $telephone; ?>" placeholder="<?php echo $entry_telephone; ?>" id="input-payment-telephone" class="form-control" />

where

$_['entry_telephone']                = '+7 (___) ___-__-__';

But at the same time, the site began to swear at the json error in the phone field.
As I understand it, this is due to the fact that I removed the name attribute. because when I returned it, the error disappeared. The problem is that this attribute again gives an unnecessary blank.

Please tell me what to do so that there is either a blank with +7 in the drop-down window, or that this drop-down window does not exist, but at the same time name = "telefone" remains with<input>