How do I deploy my watchOS app with an iOS build in TestFlight?

I am able to build and run my iOS and dependent watchOS app onto my local devices through Xcode. However, when I archive the very same build and deploy to TestFlight, the watchOS app does not get installed. The TestFlight app also shows "Apple Watch: No" for that archive.

Any help appreciated!

How do I deploy my watchOS app with an iOS build in TestFlight?
 
 
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