What if given Apple Watch was given as a gift and have no way of contacting the person that was previous to owner due to them being diseasd. How could I gain access for device?

What if given Apple Watch was given as a gift and have no way of contacting the person that was previous to owner due to them being diseasd. How could I gain access for device?I lost sibling due to corona virus unfortunately, and this is the only thing that I have left thats close that I can cherish.