function add_user($data) {
$user_table = USER_TABLE;
$first_name = ($data['first_name']);
$last_name =($data['last_name']);
$email_address = ($data['email_address']);
$drivers_license_id = ($data['drivers_license_id']);
$gender = ($data['gender']);
$password =($data['password']);
$query = "INSERT INTO $user_table (
        first_name,
        last_name,
        email_address,
        drivers_license_id,
        gender,
        password
    ) VALUES (
        '$first_name',
        '$last_name',
        '$email_address',
        '$drivers_license_id',
        '$gender',
        '$password')";
if (mysqli_query($connection,'$query',MYSQLI_USE_RESULT)) return true;
error_log("Failed to create user: " . mysqli_error($error_get_last));
return false;