Setting Default Apps in Windows Android Subsystem

Question

I have installed the Android subsystem on my Win 11 PC and then installed the Textra SMS Android app from the Amazon Appstore. The app starts, but then asks that I set this app (Textra) as "the default SMS app on my phone". I've tried setting Textra as the default SMS app in Windows 11, but that doesn't solve the problem. Here's the app running on my PC:

Can anyone tell me how to get to the default apps setting in the Windows Android subsystem to make this setting?

Thanks - Jack