How to override activation lock

Activation Lock is a theft deterrent system so you can only disable it if the watch is activation locked to an Apple ID of yours. If you're not the original owner and you cannot provide valid proof of purchase information, Apple will not remove the lock for you

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How to remove Activation Lock - Apple Support

If you didn't lock the watch with your Apple ID and Password originally, you cannot override Activation Lock. If you purchased a used Apple Watch, you've wasted your money on a useless watch you can never use, unless the real owner who locked the watch removes the watch from their account. If you don't know them or can't reach them, the watch is totally, utterly useless. Apple won't unlock it. We cannot help you unlock it.

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