In your MySwisscom customer centre:
https://www.swisscom.ch/myswisscom/d?useCase=viewMobileDeviceInfo
But in the title you write about the locked display (screen lock) - this is something else and has nothing to do with SIM unlocking
https://www.samsung.com/ch/support/mobile-devices/entsperren-mit-zuvor-verwendeter-bildschirmsperr/
….keep on rockin' 🤘🏼🤘🏼🤘🏼