Why the apple store on my watch is momentarily unavailable
We see you're having some issues with getting a 'temporarily unavailable' alert on your Apple Watch. We can certainly understand the need to have things work well. We'd like to help out.
We noted it's been a couple of days since the post, are you still experiencing issues with the same error? If so, what type of action(s) are you trying to take when you run into this error? For example, are you trying to download an app?
One particular step that may help out would be to restart both the Apple Watch, and the paired iPhone. When they turn back on, ensure that they're both connected to a good Wi-Fi connection, or cellular when applicable.
If you still experience issues, try signing out of the iTunes/App Store from the iPhone by heading to Settings > [your name] > Media & Purchases > Sign Out. Wait a moment, and sign back in. Note that if you're an Apple Music member, this step will cause any songs saved for offline use to no longer be downloaded to the device.