表单提交后$ _post仍为空

The post superglobal variable is empty after form submission; however, get works!

Here is the code:

index.php

<!DOCTYPE html>

<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Simple Form</title>
</head>
<body>
<fieldset>
    <form  action="print.php" method="POST" >
        first name:<input type="text" name="Fname"><br>
        last name:<input type="text" name="Lname"><br>
        <input type="submit" name="submit" value="submit">
    </form>
</fieldset>

</body>
</html>

print.php

<?php
echo $_POST['Fname'];
echo $_POST['Lname'];
?>

same code works fine on my PC and print.php prints something but here on my Macbook $_post is always null after submitting the form.

I use IntelliJ IDEA as my IDE with Php plugin.

I use php 7

IntelliJ is not mapped to the MAMP server. That's why php is interpreted but POST does not work. In order to map MAMP to IntelliJ use this guide which works for IntelliJ ultimate edition and PhpStorm.