It sounds like you have two factor authentication set up through Ring.com. You change this at https://support.ring.com/hc/en-us/articles/360039693891-Enhancing-Security-with-Two-Step-Verification
I have had a Ring, and Skybell doorbell camera and now have switched to Nest because of better functionality and performance. I can access my camera from anywhere and have never been asked for a verification code since I have not activated the two factor authentication on the Nest doorbell. It can be setup, for extra security, at this web location:
https://www.imore.com/how-set-two-factor-authentication-your-nest-account