TABLET DISABLED

See: If you forgot the passcode for your iPhone, iPad, or iPod touch, or your device is disabled - Apple Support

There is no way to bypass activation lock without the assistance of the previous owner. If the seller won't help, you may want to see if Mercari buyer protection will. https://www.mercari.com/us/help_center/article/22

Bought 2 ipads from Mercari. One is disable and one is lock. I have not able to contact past owners