Laravel + MongoDB:无法进行身份验证

'mongodb' => [
    'driver'   => 'mongodb',
    'host'     => env('DB_HOST', 'localhost'),
    'port'     => env('DB_PORT', 27017),
    'database' => env('DB_DATABASE'),
    'username' => env('DB_USERNAME'),
    'password' => env('DB_PASSWORD'),
    'options'  => [
        'database' => 'admin' // MongoDB默认的身份验证数据库
    ]
],

DB_CONNECTION=mongodb
DB_HOST=127.0.0.1
DB_PORT=27017
DB_DATABASE=your_database_name
DB_USERNAME=your_username
DB_PASSWORD=your_password

use Illuminate\Support\Facades\DB;

public function boot()
{
    DB::connection('mongodb')->authenticate();
}