Apple watch 1st gen cannot pair with ios 15

I have an apple watch series 1 running WatchOS 3.1.3. When setting up my watch in the watch app, I get to the Software Update screen that says "Your Apple Watch is up to date with all the latest bug fixes and security enhancements."

The only options I have are to Exit and Reset Watch or Continue Update. When I click "Continue Update" nothing happens. If I choose "Exit and Reset Watch" the watch resets and the pairing process restarts.

My iphone 12 is running ios 15.3. What should I do now? Due to connect unsuccessfully, i cannot use my watch anymore.