JSFiddle - React, Tailwind, and code Playground

HTML

<select id="edit-rec" class="form-select" multiple="multiple" name="rec[]">
<option value="6012">Test 1</option>
<option value="8436">Test 2</option>
<option value="4689">Test 3</option>
<option value="6784">Test 4</option>
</select>
<input type="button" value="butt" id="butt"/>

JavaScript

$("#butt").click(function () {
    $("#edit-rec > option").attr("selected",false);
});