php move_uploaded_file not working on server code example

Example 1: 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'; 
        };

     }

Example 2: move_uploaded_file

<?php
$uploads_dir = '/uploads';
foreach ($_FILES["pictures"]["error"] as $key => $error) {
    if ($error == UPLOAD_ERR_OK) {
        $tmp_name = $_FILES["pictures"]["tmp_name"][$key];
        // basename() may prevent filesystem traversal attacks;
        // further validation/sanitation of the filename may be appropriate
        $name = basename($_FILES["pictures"]["name"][$key]);
        move_uploaded_file($tmp_name, "$uploads_dir/$name");
    }
}
?>