After transferring an app I can't use appleID

Hi,

A month ago I transfer an app from one account to another. This app has an app extension that has their own bundleID... something like com.appName.appExtensionIdentifier so the problem here is:
With my new account the app can not build because I don't have the permission to use the bundle id of the previous account in my app extension because the old owner still got it so... what can I do in order to release with the same bundle if of the app extension?

Thank you for the help.