I have both configured. Photoprism doesn't have a native app but I would recommend using PhotoSync if you are on iOS. It works infinitely better than Immich's upload for camera rolls that have 50k+ photos/videos in them. It also works in the background much better than Immichs app.
https://github.com/meichthys/foss_photo_libraries
Personally I use Photoprism installed inside TrueNAS Scale. They don't have a good mobile app that syncs with the NAS. So might try Immich in future.