move_uploaded_file() not working in php code example

Example: php move_uploaded_file

$upload_folder = "upload/";
$file_location = $upload_folder . basename($_FILES["fileToUpload"]["name"]);

     if(isset($_FILES['fileToUpload'])){ 

        if(move_uploaded_file($_FILES['fileToUpload']['tmp_name'], $file_location)){
            
            echo 'Files has uploaded'; 
        };

     }