I faced the same issue while uploading ionic3 app on testflight.
After exploring I found the blog "Understanding ITMS-90809: UIWebView API Deprecation" by Matt Netkow,
following the mentioned steps resolves the issue.
Remove the ios platform using cmd:
ionic cordova platform rm ios
2. Check plugin cordova-plugin-ionic-webview in package.json file. If not included then add plugin using cmd:
ionic cordova plugin add cordova-plugin-ionic-webview
3. Add the ios platform with version 5.1.0 using cmd:
ionic cordova platform add ios@~5.1.0
4. Check <preference name="WKWebViewOnly" value="true" /> in config file. if not present then add it.
5. Run cmd:
npm i
6. Run cmd
ionic cordova build ios
Then open project in xcode and archive the build.
Hope this will help you in uploading the ionic3 app build on testflight.
AshishSuhane
Users receive reputation points by contributing quality content to the forums.
Posts include post and replies published on the forums.
Post authors can mark replies as Accepted to indicate successful solutions.
Apple Developer Forums admins can mark replies as Apple Recommended to indicate an approved solution