How do I make PHP form in CodePlayground?

Question

How can I create a PHP form in CodePlayground if it's only available for me one file per project? I wanted to do a form like following.
<form action="file.php" method="post">
Name: <input type="text" name="name"><br>
Age: <input type="text" name="age"><br>
<input type="submit">
</form>
The problem is, what action will I put if I have no external files?

Answer 1

Now I start to ask myself what's utility of the PHP codeplayground...

Answer 2

It's not possible in SoloLearn as far as I know.