The first step when registering an app in the App Store is retrieving a bundle ID. This is a unique identifier. This identifier can be used for an app or other objects, including websites that use sign-in with Apple, push IDs, or iCloud containers.
The configuration of a bundle ID requires choosing a description, the bundle ID itself, and the capabilities of your app.
The configuration process gives you the option to choose an explicit or wildcard bundle ID. You must choose an explicit bundle ID if you want to enable push notifications or in-app purchases. If you choose a wildcard bundle ID, just leave an asterisk in the text field.
As the bundle ID must be universally unique (there cannot be another app with the same bundle ID in all the Apple ecosystems), Apple suggests using the reverse domain name notation: ext.yourdomain.yourappname. You can choose either an existing domain if you have one, your name and surname, or any other name that might be unique...
