An App ID with Identifier 'com.example.app.extention' is not available. Please enter a different string

Question

I have tried to add extensions to my iOS app, both a today extension and an Apple Watch app. My app has been completed however when submitting my archive I got the error bas

Answer 1

As far as I know, a bundle ID must have the form com.yourCompany.yourApp. App IDs are used to identify your app among all other millions of apps on the store and have to be unique.

Someone probably already created this ID com.example.app.extention. This is why you are seeing the error message.

You must used something unique, that identifies your company and your app or you and your app.