Plugin fails ever and ever again

Hey,
I am making a Plugin for my Site. This Plugin gets his input from the Html Forms. But it doesnt work. At first i tried something like this:

< html>

<form action="test.php" method="post">
Name: <input type="text" name="name"><br>
E-mail: <input type="text" name="email"><br>
<input type="submit">
</form>

</body>
</html> 

And on the .php file:

<html>
<body>

Welcome <?php echo $_POST["name"]; ?><br>
Your email address is: <?php echo $_POST["email"]; ?>

</body>
</html> 

( I called the File test.php and put it in the pages folder )

It didnt worked so i decided to make a Plugin with the new Devtools Plugin. Because it didn’t worked i followd step by Step the Grav Documention about it. —> i had excettly the Same Code but it still didn’t work.
Can Someone please Help me? :confused:

Greatings,

Niels

@Niels It makes me curious about which docs you followed step by step. Would you mind sharing the url?