Resetting Apple Watch without Apple ID password

If this is about the Activation Lock and you have proof of purchase, you can contact the official Apple Support and ask them to disable the Activation Lock. Have a look at the information in this article:

Additional Support - Activation Lock

In case this is about the forgotten passcode for the Lock Screen of your Apple Watch, follow the steps mentioned here:

If you forget your Apple Watch passcode - Apple Support

How did you post here in the Apple Support Communities if you don't know your Apple Account password?

It appears the watch is under Activation Lock. This Lock prevents lost and stolen devices from being used by others. Only the original owner of the device can remove the Activation Lock.

M1 Mac mini, macOS 15.2;  Watch, series 10 GPS-only, watchOS 11.2; iPhone 16, iOS 18.2.1; TV 4th Gen, tvOS 18.2; HomePods, audioOS 18.2 and Airport Express w/ Airplay 2