验证码不能在laravel 5.7中验证

Question

I have installed and configure one captcha package from this url Captcha Module in login page.

While user login at that time must need captcha and verify it but somehow it will not work.

If i have enter any wrong text and then press submit. it will submit the page and not throw any error message regarding wrong captch code. Login Page

LoginController.php

public function loginSubmit(Request $request)
{
    $validator = Validator::make($request->all(), [
        'email' => 'required|max:255',
        'password' => 'required',
        'captcha' => 'required|captcha'
    ]);

    if ($validator->fails()) {
        return redirect('login')
                    ->withErrors($validator)
                    ->withInput();
    }else{
       $details = $request->only('email', 'password');  
       if (Auth::attempt($details)) {
            return redirect('dashboard')->with('status', 'Login Success!');
       }
    }
}

Does i missed something ?

Thanks