In the end I found out that SwiftUI is only supported from Xcode 11 on.

I just got the "credentials" error also in the original location, so it did not have anything to do with the location. I solved the problem in that I quitted Xcode and started it again. Then everything worked again, including "distribute".

I don't know why, but the Appstore now shows the 3 screenshots.

I have found a way to retract holidays from the stock apple calendar (via EKEventStore().events(matching: mypredicate)

I only cited a part of the code here above, which is in the main App swift file (The creation of the notification is, as usual, in another file). I cited this part, because I presume, but do not know, that it has something to do with launchOptions or completionHandler. Hope someone has an idea.

Thanks Timo23, your idea completionHandler([.alert, .badge, .sound]) pushed me in the right direction that it has to do with the characteristic of the banner. Although it did not really work to start with: I changed .banner to .alert but the notification still came as banner disappearing after some seconds. In the end I found out that my app has the following Settings page : Tapping "Notifications" brings up following page: where you can set the "Banner Style" to "persistent". Now the banner does not disappear anymore. One little disadvantage: the user has to perform this action, I have not found a way to do it programmatically.

Mind if you select YES your address (or P.O. Box), tel. nr. and email address will be displayed in the App Store, at least acc. to https://developer.apple.com/help/app-store-connect/manage-compliance-information/manage-european-union-digital-services-act-compliance-information/ If you do not want that , NO is a good option. But when you publish a payed app, or at least one with a payed option, you probably have to select YES, although this is not explicitly clear, especially if you are just a hobby programmer "trying out" in-app-purchases. I have a non-payed app published and was considering to try out in-app-purchases, still rather as a hobby and as a learning activity. However I now doubt to start with that, I do not want my personal address published. Also, you never know which burocratic further demands will follow, (and all that because of a hobby where maybe only a friend pays once $1.99 for an in-app purchase.)