JSFiddle - React, Tailwind, and code Playground

HTML

<div>
        <label for="naming_dir_pattern">
            <span>Custom</span>
            <input type="text" value="" id="custom_pattern" name="custom_pattern" size="50"><br />
        </label>
        <br/>
        <label>
            <span>
                <input type="button" class="setNamePattern" value="1111">
                <input type="button" class="setNamePattern" value="2222">
            </span>
        </label>
    </div>

JavaScript

$('.setNamePattern').on("click", function(){
      $('#custom_pattern').val( $(this).val() );
  });