How can I create a div that, when written into the markup, inserts certain code?

Question

PHP

<div id="page">

      <div class="menu">
        <button class="btn" type="button" id="modal_open">Заказать звонок</button>
      </div>

     
                                         

    <div class="modal-overlay" id="modal_window"
             aria-hidden="true" role="dialog"
             aria-labelledby="modal_title">

      <div class="modal-content" id="modal_holder" role="document">

          <h1 id="modal_title">Заказать звонок</h1>
          <form>
            <label for="name">Имя:</label>
            <input type="text" id="name" class="input" placeholder="Ваше имя" />

            <label for="tell">Номер телефона:</label>
            <input type="tell" id="email" class="input" placeholder="Ваш номер телефона" />

            <input type="submit" class='btn' value="Отправить" />
          </form>

        <button class="btn-close" id="modal_close" type="button" aria-label="close">
          &times;
        </button>

      </div> <!-- end .modal-content -->

    </div> <!-- end .modal-overlay -->

here is the html markup that adds a "button" to order a callback.

This markup is too cumbersome to insert every time I want to have such a button.
that is, I just want to
get such a button by inserting
PS, I'm on vorpress.
Thank you.

Answer 1

<button class="btn" type="button" id="modal_open">Заказать звонок</button>

- here is the button, it can be duplicated at least 100 times on the page, but the rest can be written once (call order block)