I need help of activation lock in apple watch

The original owner of the watch has to do this;

You can request an Online Activation Lock Removal here.

Or this;

If you can't remember/gain access to the apple id that paired the watch to the phone.Take the watch and it's receipt along with some photo id and any other proof of ownership to an Apple Store and request that they remove the Activation Lock for you.

Otherwise the watch will be of no use to you.

The person that you bought this watch from needs to follow all the steps in this link;

Prepare the watch so the buyer can use it.

If they can't or won't then get your money back or recycle the watch and put it down to experience.

Is this a used Watch? Do you know the owner?

Activation Lock keeps a lost or stolen Watch from being used by someone else. Only the owner of the watch can remove the Activation Lock.

M1 Mac mini, macOS 11.3.1; Watch, series 5 GPS/cellular, watchOS 7.4.1; iPad Pro 2nd Gen, iPadOS 14.5.1; iPad Air 2, iPadOS 14.5.1; iPhone 12 Pro, iOS 14.5.1; TV 4th Gen, tvOS 14.5  HomePods, audioOS 14.5 and Airport Express w/ Airplay 2