No data response when sending ajax request to php

I want to send a json data to my php but when i access it to my php there is no response.

this is my ajax request

    var project = {project:"A"};

 var dataPost = JSON.stringify(project);

     $.ajax({
     url: 'fetchDate.php',
     data: {myData: dataPost},
     type: 'POST',
     datatype:'json',
     contentType: "application/json",  
     success: function(data) {
         alert(JSON.stringify(data));
     }
 });

});

Here is my php where I handle the request and return the data for testing

<?php header("Content-Type: application/json; charset=UTF-8");
  $objProject = json_decode($_GET["myData"]);
  echo json_encode($objProject->project); ?>

I am new to ajax so please i need your help