Laravel Passport：API Guard的提供者返回null

Question

我有一个使用Laravel 5.7和Passport的API。我正在尝试在调用API时从Guard中获取用户提供程序，但是API Guard仅返回null。

当我使用dd（auth（））时，我得到以下信息：

#guards: array:2 [▼
    "web" => SessionGuard {#489 ▼
      #name: "web"
      #lastAttempted: null
      #viaRemember: false
      #session: Store {#492 ▶}
      #cookie: CookieJar {#493 ▶}
      #request: Request {#55 ▶}
      #events: Dispatcher {#35 ▶}
      #loggedOut: false
      #recallAttempted: false
      #user: null
      #provider: EloquentUserProvider {#483 ▼
        #hasher: HashManager {#488 ▶}
        #model: "App\User"
      }
    }
    "api" => RequestGuard {#526 ▼
      #callback: Closure {#527 ▶}
      #request: Request {#55 ▶}
      #user: User {#655 ▶}
      #provider: null
    }
]

在我的config / auth.php文件中：

'guards' => [
    'web' => [
        'driver' => 'session',
        'provider' => 'users',
    ],

    'api' => [
        'driver' => 'passport',
        'provider' => 'users',
    ],
],

'providers' => [
    'users' => [
        'driver' => 'eloquent',
        'model' => App\User::class,
    ],
],

要进行这项工作，我还需要设置其他配置吗？