Are you setting up on a or a device without Google Play Services ?
Go to Android Settings > Apps > Google Play Store > Storage, and tap Clear Cache . Do the same for Nova Launcher.
If you own a legitimate authorization code or Play Store license but keep getting validation errors, use these troubleshooting steps to fix the issue. "License Verification Failed" Error
Modified APKs found on third-party websites frequently bundle hidden spyware, adware, and trojans designed to steal your personal data.
If you lose access to the email address tied to your authorization code, you will need to contact Nova Launcher support with proof of purchase to migrate your license to a new email address.
If you purchased Nova Launcher Prime through the Google Play Store, you do not actually receive a text-based authorization code.
Ensure the primary email address logged into your device's Google Play Store matches the exact email address you used to purchase Nova Launcher Prime.
If you search the internet for a leaked "Nova Launcher Prime authorization code and email," you will likely find websites claiming to offer free activation keys, patched APKs, or premium account credentials.
Using pirated versions can result in your Nova Launcher configuration being blacklisted from cloud backups.