Apple Watch/ can’t open

Watches are Activation Locked to the owner's Apple ID to prevent someone else from using a lost or stolen watch.

There isn't anything that you can do besides perhaps turning it in at the local police station. Apple won't help you find or contact the owner.

M1 Mac mini, macOS 13.5.2;  Watch, series 7 GPS/cellular, watchOS 10.0.1; iPad Pro 2nd Gen, iPadOS 17.0.1; iPhone 12 Pro, iOS 17.0.1; TV 4th Gen, tvOS 17; HomePods, audioOS 17 and Airport Express w/ Airplay 2

Activation Lock is designed to prevent anyone else from using an Apple Watch if it's ever lost or stolen.

About Activation Lock on your Apple Watch - Apple Support

Activation Lock is an anti-theft feature that cannot be bypassed. Only the previous owner can remove the lock by using their Apple ID & password. Apple will not help you find the previous owner. If the previous owner cannot or will not remove the lock, then the watch is useless to you or anyone else. Turn it over to the authorities or dispose of the watch properly.

Thanks for trying. Sorry I couldn't be more helpful.