در جاوا اسکریپت خروجی کد زیر undefined هست و در network chrome مقدار 0 برمیگردونه

let message = error.responseJSON.message;

    $user = wp_authenticate_username_password(null, $userEmail, $userPassword);
    if (is_wp_error($user)) {
        wp_send_json([
            'success' => false,
            'message' => 'there is not user match',
        ], 403);
    }
    $loginResult = wp_signon([
        'user_login'    => $user->user_login,
        'user_password' => $userPassword,
        'remember'      => false
    ]);
    if (is_wp_error($loginResult)) {
        wp_send_json([
            'success' => false,
            'message' => 'try it later'
        ], 403);
    }
    wp_send_json([
        'success' => true,
        'message' => 'Successful Login'
    ], 200);