Translated by google:
>>Apple Watch locked by owner after subscription cancellation
Hello. Two months ago, I unpaired the watch, and it has just been sitting at home since then. Now I want to pair it again, but it says the watch is locked by the owner—even though no one but me has touched it. I enter all the details, but it says they are incorrect. What should I do?<<
Did you buy the Apple Watch, or did it have a previous owner?
If this case, only the previous owner can disable the Activation Lock for the Apple Watch, which can also be done via the iCloud Account over the Web:
About Activation Lock on your Apple Watch - Apple Support
If you are the original owner and you have proof of purchase or ownership, as explained in this related article, the official Apple Support can disable the Activation Lock:
Additional Support - Activation Lock