api路由設置

<?php

use Illuminate\Http\Request;

/*
|--------------------------------------------------------------------------
| API Routes
|--------------------------------------------------------------------------
|
| Here is where you can register API routes for your application. These
| routes are loaded by the RouteServiceProvider within a group which
| is assigned the "api" middleware group. Enjoy building your API!
|
*/

Route::middleware('auth:api')->get('/user', function (Request $request) {
    return $request->user();
});

Route::get('/index', 'HomeController@index');

Route::post('/submit', 'HomeController@submit');

控制器代碼

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;

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

    public function submit(Request $request)
    {
        $this->validate($request, [
            'name' => 'required|max:3',
        ]);

        echo 'validate success';
    }
}

錯誤提示