We have developed a Watch App for our React-Native IOS app using SwiftUI. After the the integrations are completed, we've tried to upload the build to TestFlight for testing purposes. In the process, since enabling bitcode is mandatory for WatchOS apps, it is enabled through Project Target -> Build Settings -> Build Options -> Enable Bitcode : Yes (And also tried to enable bitcode for Pods target). However, there is no other option to enable bitcode in the Watch Targets (both watch app and watchkit extension).
When we tried to upload the build to TestFlight, it got rejected with the error code ITMS-90496: Invalid Executable - The executable "{ProjectName}/Watch App WatchKit Extension.appex/WatchKit Extension" does not contain bitcode.
I have also read that in order to make the whole project bitcode enabled, you need to make sure that the libraries are also bitcode compatible. And since the app is a React-Native app, it contains a lot of 3rd party libraries. If anyone who tried to add a Watch App to an existing React-Native project and managed to upload it to TestFlight can help us during the process, it would be really helpful.
For those who are experiencing the same issue, our was in RN 0.63.* version, and the third party libraries were kind of old as well. After upgrading both RN and the third party library versions, the issue is gone and we're now able to upload to Testflight!