Thanks for the valuable hint.
Didn’t realise that a different offer would be made available via Swisscom?
In other words, if I log in with my normal Amazon login via the Amazon Prime app on the Swisscom box, will I receive the AmazongPrime DE offers if I have booked them via the Amazon DE website? Or does Amazon Prime have different offers on a computer than on the app, even if I never pay via Swisscom but only via Amazon.de?