How to set the Apple Watch Ultra Action button and sound or stop the siren

To change what the Action button does on Apple Watch Ultra, open the Settings app, tap Action Button, tap Action, then pick a function such as Workout, Backtrack or Dive. The same button sounds the siren: press and hold it, wait for the countdown to finish, and the watch starts an alarm meant to attract help. Apple Watch Ultra 4 on the wrist....