Facebook login Access token is nil (iOS)

Hello, I integrated the connection with facebook and firebase. when I try the button in the simulator, everything is fine. but when I test it on the iPhone, I get this error message

[Thread 1: Fatal error: Unexpectedly found nil while unwrapping an Optional value]! Capture d’écran 2020-06-14 à 00.06.50|690x89

Please Help me