JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://code.jquery.com/jquery-3.2.1.min.js"></script>
<div>
    <table>
      <thead>
        <tr>
          <th>Userid</th>
          <th>E-Mail</th>
          <th>Phone</th>
          <th>&nbsp;</th>
        </tr>
      </thead>
      <tbody>
        <tr>
          <td>1</td>
          <td>test@test.ch</td>
          <td>000 000 0000</td>
          <td>
              <button type="button" name="delete" class="userdeletion" data-attr-userid="1">Delete</button> 
          </td>
        </tr>
        <tr>
          <td>2</td>
          <td>test@test.ch</td>
          <td>000 000 0000</td>
          <td>
              <button type="button" name="delete" class="userdeletion" data-attr-userid="2">Delete</button> 
          </td>
        </tr>
        <tr>
          <td>3</td>
          <td>test@test.ch</td>
          <td>000 000 0000</td>
          <td>
              <button type="button" name="delete" class="userdeletion" data-attr-userid="3">Delete</button> 
          </td>
        </tr>        
      </tbody>
    </table>
</div>

JavaScript

$(function() {
	$('.userdeletion').on('click', function() {
  /* Remove this line, after you understood, how its going */
	alert($(this).attr('data-attr-userid'));
  $.ajax({
      type: "POST",
      url: 'scripts/child_user.php',
      data: '&user_id='+$(this).attr('data-attr-userid'),
      success: function(data) {
          $("#del_msg").html(data);
      }
    });
  });
})