Sometimes, you just need to update Google Pay:

FIND GOOGLE ERROR CODES SEARCH

Open the Google Pay app on your smartphone's app store

Look for an update in the app store

If there is an update, install it

Wait for it to finish installing

Restart Google Pay and sign-in

Reinstall Google Pay on your smartphone

Open the app store on your smartphone

Look for Google Pay

Search for the Google Pay app

Uninstall it

Once the app is installed, reinstall it

Try to sign in again after the installation

If the issue persists, try again