laravel-beginning/form-app/app/Http/Controllers/FormController.php

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;

class FormController extends Controller
{
    public function index() 
    {
        return view('form');
    }

    public function submit(Request $request)
    {
        $validated = $request->validate([
            'name' => 'required|min:3',
            'email' => 'required|email',
            'message' => 'required|min:10'
        ]);

        return back()->with('success', 'Форма успешно отправлена! Привет, ' . $request->name);
    }
}