What is the exact message? Are you able to use the device if you say not now? "Verification" usually requires getting a verification code, but if you are able to use the device without that then it may be some other service asking for verification. For example, in the support article: If you subscribe to Apple One and use a different Apple Account for iCloud - Apple Support Apple alludes to using a different Apple ID just for media, subscriptions, and purchases, but doesn't describe how to do this. See if these work:
In iOS/iPadOS: Go to Settings > [your Apple ID] > Media & Purchases. Sign out of the current ID and sign in with a different one.
Is this a new (as in never before used by anybody) device, or did it have a previous owner? If it did, there could be residual features set on it which should have been removed when it was reset properly.