HTTP 405 error when ajax function calls PHP script

See more:

Javascript

PHP

HTML5

I am trying to call the php script with the help of AJAX and send some values acquired from an html form. My code editor is Microsoft Visual Studio Code.

My code:

function submit(a,b,c,d,em){
    
        console.log(a+" "+b+" "+c+" "+d+" "+em)   //shows the values correctly
    
        $.ajax({
            type : "POST",  //type of method
            url  : "script.php",  //your page
            data : { a:a, b:b, c:c, d:d, e:em },// passing the values
            success: function(){  
                                    //do what you want here...
                                    alert("ok");
                    }
        });
    
        
    }
    
    const dForm = document.getElementById('form');          
    dForm.addEventListener('submit', function(e) {
        e.preventDefault()
        submit(a,b,c,d,em);
    });

When I run the script, I get this error in the console:

Failed to load resource: the server responded with a status of 405 (Method Not Allowed)

Please help me in fixing this.

Here's my php script:

<?php
        header('Access-Control-Allow-Origin: *');
        header("Access-Control-Allow-Methods: GET, POST, OPTIONS");

        if (isset($_POST["a"]))
            $val_1=$_POST['a'];
        if (isset($_POST["b"]))
            $val_2=$_POST['b'];
        if (isset($_POST["c"]))
            $val_3=$_POST['c'];
        if (isset($_POST["d"]))
            $val_4=$_POST['d'];
        if (isset($_POST["e"]))
            $val_5=$_POST['e'];
    ?>

What I have tried:

Included both the core headers, but still it doesn't work (in my php scirpt).