Yes indeed the Apple App Store is not compatible with GNU GPL v3 licence. Maybe MOL MPLcan suits your needs.
However plenty of open source apps under GPL v3 or AGPL v3 are available on the App Store and Apple does not care.
For example:
- https://github.com/Dimillian/IceCubesApp (Mastodon client)
- https://github.com/mlemgroup/mlem (Lemmy client)
- https://github.com/CovidTrackerFr/vitemadose-ios (COVID vaccines app)
Yup, I meant Mozilla Public License