If you are the original owner, Google Support or DOOGEE customer service can often assist with verification if you provide proof of purchase.
Connect your tablet to the PC via USB while it's on the Google verification screen. Bypass Google Verification on DOOGEE U9 Kid
Bypassing Google Verification (FRP) on the DOOGEE U9 Kid is a process typically required after a factory reset if the original Google account credentials are forgotten. If you are the original owner, Google Support