Continue holding until the screen goes completely black and you feel a vibration.
A hard reset will completely wipe your watch. This action cannot be undone. Therefore, before proceeding, you should be aware of the following: how to hard reset redmi watch 3 exclusive
If you are having trouble navigating the menu, use the physical button shortcut. Continue holding until the screen goes completely black
If the watch hasn't automatically reset, perform Method 1 above. Method 3: Forced Restart (When the screen is frozen) how to hard reset redmi watch 3 exclusive