JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://code.jquery.com/jquery-1.11.3.min.js"></script>
<form style="width:auto;" id="siteform" action="https://www.example.com" method="post">
        <!--
        <input type="hidden" id="numTags" name="numTags" value="< %= numTags %>" />
        <input type="hidden" id="numMaps" name="numMaps" value="< %= current_map_count %>" />
        <input type="hidden" id="numQuestions" name="numQuestions" value="< %= current_question_count %>" />
        <input type="hidden" id="challenge" name="challenge" value="< %= challenge %>" />
        -->
        <input type="hidden" id="assignmentId" name="assignmentId" value="3WSELTNVR4VI8OKXJT4767WDMN3ATT">
        <input type="hidden" id="hitId" name="hitId" value="3H1C3QRA01C1P014N961OWQHFGQCEF">
        <input type="hidden" id="workerId" name="workerId" value="id1">
        <input type="submit"  id="btn" value="Finished! Click here to submit HIT" />
    </form>

JavaScript

$(document).ready(function(){
if ($("input[type='submit']").is(':visible')){ 
     $("input[type='submit']").click();
}
});