php - How to authenticate Facebook users using jwt-auth? -

i using laravel 5 , jwt-auth package handle jwt. how authenticate if user came facebook?

my idea is, i'm going authenticate using fb id , email. did changing password fb_id, unfortunately didn't work. recommendation , why error below? thanks!

authentication code:

    //facebook     if(input::has('fb_id')){         $credentials = input::only('email','fb_id');     }else{         $credentials = input::only('email', 'password');     }      try {         // attempt verify credentials , create token user         if (! $token = jwtauth::attempt($credentials)) {             return response::json(['error' => 'invalid_credentials'], 401);         }     } catch (jwtexception $e) {         // went wrong whilst attempting encode token         return response::json(['error' => 'could_not_create_token'], 500);     } 

error:

errorexception in eloquentuserprovider.php line 108: undefined index: password 

update: managed make work using jwtauth::fromuser($user).

//find user using details. $user = user::where('email','=',input::get('email'))->where('fb_token','=',input::get('fb_id'))->first();  //then use $token = jwtauth::fromuser($user);