2FAuth/app/Http/Controllers/Auth/ForgotPasswordController.php

<?php

namespace App\Http\Controllers\Auth;

use Validator;
use App\Http\Controllers\Controller;
use Illuminate\Http\Request;
use Illuminate\Foundation\Auth\SendsPasswordResetEmails;

class ForgotPasswordController extends Controller
{
    /*
    |--------------------------------------------------------------------------
    | Password Reset Controller
    |--------------------------------------------------------------------------
    |
    | This controller is responsible for handling password reset emails and
    | includes a trait which assists in sending these notifications from
    | your application to your users. Feel free to explore this trait.
    |
    */

    use SendsPasswordResetEmails;

    /**
     * Create a new controller instance.
     *
     * @return void
     */
    public function __construct()
    {
        $this->middleware('guest');
    }

    /**
     * Send a reset link to the given user.
     * Override native function to validate if email to reset exists
     *
     * @param  \Illuminate\Http\Request  $request
     * @return \Illuminate\Http\RedirectResponse|\Illuminate\Http\JsonResponse
     */
    public function sendResetLinkEmail(Request $request)
    {

        $this->validate($request, ['email' => 'required|exists:users,email']);

        // We will send the password reset link to this user. Once we have attempted
        // to send the link, we will examine the response then see the message we
        // need to show to the user. Finally, we'll send out a proper response.
        $response = $this->broker()->sendResetLink(
            $this->credentials($request)
        );

        return $response == Password::RESET_LINK_SENT
                    ? $this->sendResetLinkResponse($request, $response)
                    : $this->sendResetLinkFailedResponse($request, $response);
    }
}