Try Now button does not show up

[harpreps]

Hello,
I followed your samples to create a test instant app with a single module. When I upload the signed bundle to the 'instant app only' track on the play console and release it to internal test users, they only see a 'Install' button. The only opt-in link to share is in the test users section in 'Standard' track and not in the instant app track. Can you please shed some light on what might be missing?
I believe I have everything set up correct in the manifest and the build files. I followed the answer to this to upload the bundle to play console: https://stackoverflow.com/questions/65918686/instant-app-try-now-button-does-not-appear-in-play-store

Thank you