php - Fatal error: Call to a member function fetch_assoc() on a non-object

how do i fix this error? this is my code.

$stmt = $this->conn->prepare("SELECT ngno, email, encrypted_password, name, user_type FROM `guide` WHERE email = ?");

    $stmt->bind_param("s", $email);

    if ($stmt->execute()) {
        $user = $stmt->bind_result($ngno, $email, $encrypted_password, $name, $user_type)->fetch_assoc();

        $stmt->close();

im using a remote sql database. i have also tried this on my localhost. but then i get the error, fatal error call to a member function fetch_assoc() on boolean

this code worked with get_result instead of bind_result. but i need to use bind_result. Any help would be appreciated.

EDIT 1:

i have changed the code to the following,

$stmt = $this->conn->prepare("SELECT ngno, email, encrypted_password, name, user_type FROM `guide` WHERE email = ?");

    $stmt->bind_param("s", $email);

    if ($stmt->execute()) {
        $stmt->bind_result($ngno, $email, $encrypted_password, $name, $user_type);
        $user = $stmt->fetch_assoc();
        $stmt->close();


        if($encrypted_password == $password){
            return $user;
        }
    } else {
        return NULL;
    }

i get this error now. Fatal error: Call to undefined method mysqli_stmt::fetch_assoc()

Is my query failing?