exchange/app/Http/Controllers/Auth/ForgotPasswordController.php

<?php

namespace App\Http\Controllers\Auth;

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

class ForgotPasswordController extends Controller
{
    use SendsPasswordResetEmails;

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

    /**
     * Get the response for a successful password reset link.
     *
     * @param  string  $response
     * @return \Illuminate\Http\RedirectResponse
     */
    protected function sendResetLink(Request $request)
    {   
        if($request->input('email')) {
            $this->sendResetLinkEmail($request);
        }
        
        return response()->json([
            'error' => false,
            'email' => $request->input('email'),
        ]);
    }

    /**
     * Get the response for a failed password reset link.
     *
     * @param  \Illuminate\Http\Request $request
     * @param  string  $response
     * @return \Illuminate\Http\RedirectResponse
     */
    protected function sendResetLinkFailedResponse(Request $request, $response)
    {
        return response()->json(['email' => trans($response)], 400);
    }
}