Routing

Controller File Modified

class IndecController extends Controller
{
    //
    public function index(){
        return inertia('Index');
    }

    public function about()
    {
        return inertia('About');        
    }
}

Web.php

Route::get('/', ['App\Http\Controllers\IndecController', 'index']);


Route::get('/about', ['App\Http\Controllers\IndecController', 'about']);