I need to make a form submission. At the moment I have created a post with has the URL…

http://localhost:8888/japan/quiz/

… and includes a form with the following html:

<form id="quiz" action="http://localhost:8888/japan/grade.php" method="post">
<radio buttons>
</form>

The grade.php form is my main folder (child theme folder), but if I press submit I just get a 404 page. I would like to know:

• (1) Where do I need to place the grade.php file in my child-theme
  directly (or where does the action link need to point to)
• (2) What do I change the action URL to so that I don’t need to alter the html when the site goes live?

Thank you!