I'm creating some Chrome extension and I need to have a connection to a database. I followed a tutorial from
Everything works fine except when I run XMLHttpRequest my responseText is the code of my PHP. 
JS from popup.js:
let xhr = new XMLHttpRequest(); 
xhr.open(   "GET",   chrome.extension.getURL("/create.php?mail=" + mail.value),   true ); 
xhr.onreadystatechange = function() {   if (xhr.readyState == 4) {
            console.log(xhr.responseText);
            response.innerHTML = xhr.responseText;   } }; 
xhr.send();
PHP from create.php:
echo "something";
 
    