AymenBenaidja
Did you try downloading the App by scanning the QR code on your watch?
If so, then you would need to download an older version of the app that will allow you to use it with your phone without any issues.
Or @Menguelez can support you with that since he has more experience with those problems 😅
The option to download an APK is ruled out because you use iOS and well that would be an obstacle.