sharing data between iPhone apps
How do I export activity data from Apple Health app to 99 walks app?
iPhone 12 mini, iOS 15
Question marked as
You can turn on data sharing for apps in Health or Privacy settings if the specific app supports it: See here: link-> Share your data in Health on iPhone - Apple Support
If the specific app supports XML files, you can export your health data to an XML file you can then import into the app.