I sold my Pixel and thought I removed my account but..

But now they're needing my account info in order to get into the device. I definitely want to get them access to the account but don't want to give them access to my Google account.

What are my options here? Can I remotely allow it or remove it from the device?

UPDATE: Google support is damn amazing. They offered to not only contact the buyer himself, but transfer the purchase into his name and then replace the device for him so that I don't have to give him any of my info, and the device will work for him.