我正在嘗試在用戶注冊時向他們發(fā)送電子郵件驗證鏈接，但我收到一條消息Authentication required，但沒有發(fā)送郵件。我嘗試將 mailtrap 用于演示和 sendgrid，我將在生產(chǎn)中使用它們，但消息是相同的。這就是我要做的運行后，composer require guzzlehttp/guzzle我像這樣更新了我的 env 文件# MAIL_DRIVER=smtp# MAIL_HOST=smtp.mailtrap.io# MAIL_PORT=2525# MAIL_USERNAME=mailtrap_username# MAIL_PASSWORD=mailtrap_password# MAIL_ENCRYPTION=tlsMAIL_DRIVER=smtpMAIL_HOST=smtp.sendgrid.netMAIL_PORT=587MAIL_USERNAME=sendgrid_usernameMAIL_PASSWORD=sendgrid_passwordMAIL_ENCRYPTION=tls在控制器中，我想在這樣成功創(chuàng)建用戶后發(fā)送郵件...use App\Mail\VerifyEmail;...use Illuminate\Support\Facades\Mail;public function register(Request $request){    // create and store new user record    $user = User::create([        'username'  => $request->username,        'password'  => bcrypt($request->password)    ]);    // send user email verification link    Mail::to($user->username)->send(new VerifyEmail());}驗證郵件.php<?phpnamespace App\Mail;use Illuminate\Bus\Queueable;use Illuminate\Mail\Mailable;use Illuminate\Queue\SerializesModels;use Illuminate\Contracts\Queue\ShouldQueue;class VerifyEmail extends Mailable{    use Queueable, SerializesModels;    /**     * Create a new message instance.     *     * @return void     */    public function __construct()    {        //    }    /**     * Build the message.     *     * @return $this     */    public function build()    {        $from = 'support@fromus.com';        $name = 'custom name';        $subject = 'Welcome! Confirm Your Email';        return $this->from($from, $name)            ->subject($subject)            ->view('auth.verify');    }}按照電子郵件驗證文檔https://laravel.com/docs/5.8/verification#verification-routing我添加了Auth::routes(['verify' => true])這樣的api.php文件<?php// Register routes for email verificationAuth::routes(['verify' => true]);Route::prefix('v1')->group(function () {    // protected routes    Route::middleware('auth:api')->group(function () {        Route::get('products', 'ProductController@index'); // get products    });});為什么我會收到Authentication required錯誤消息，我該如何解決？