Singleton, class / instance injection

Hey, I would like to create ONLY one instance of a class and use it several times in my UserController. I set up a singleton in AppServiceProvider (hopefully correctly) like:

$this->app->singleton('skautis', function ($app) {
            $config = new Config(env('SKAUTIS_APP_ID'), true, true, true);
            $sessionAdapter = new \Skautis\SessionAdapter\SessionAdapter();
            $webServiceFactory = new \Skautis\Wsdl\WebServiceFactory();
            $wsdlManager = new WsdlManager($webServiceFactory, $config);
            $user = new SkautisUser($wsdlManager, $sessionAdapter);
            return new Skautis($wsdlManager, $user);
        });

and then I access the instance in UserController by app('skautis').

In this callback I set user login data:

public function loginSkautisCallback(Request $request, )
    {
        try {
            app('skautis')->setLoginData($request->all());
        } catch (\Throwable $th) {
            toast()->warning('Přihlášení se nezdařilo.')->pushOnNextPage();
            return redirect('/');
        }
}


//dd(app('skautis')); will correct user data:

Skautis\Skautis {#598 ▼ // app\Http\Controllers\UserController.php:286
  -wsdlManager: Skautis\Wsdl\WsdlManager {#593 ▶}
  -user: Skautis\User {#597 ▼
    -wsdlManager: Skautis\Wsdl\WsdlManager {#593 ▶}
    -session: Skautis\SessionAdapter\SessionAdapter {#586 ▶}
    #loginData: array:4 [▼
      "ID_Login" => "3615c778-7443-602u-9r23-0d004a70q738"
      "ID_Role" => 10632
      "ID_Unit" => 37567
      "LOGOUT_Date" => DateTime @1673272203 {#600 ▶}
    ]
  }
  -log: null

but I can't access it in another function:

public function importSkautis()
    {
        dd(app('skautis'));
    }

//returns empty object:

Skautis\Skautis {#1360 ▼ // app\Http\Controllers\UserController.php:309
  -wsdlManager: Skautis\Wsdl\WsdlManager {#608 ▶}
  -user: Skautis\User {#1362 ▼
    -wsdlManager: Skautis\Wsdl\WsdlManager {#608 ▶}
    -session: Skautis\SessionAdapter\SessionAdapter {#1427 ▼
      #session: & []
    }
    #loginData: []
  }
  -log: null
}

My point is to set user data in one function and work with the user (the instance) in another function.