Decided to reset the Macbook. Got MacOS 10.8.5 installed. Trying to update to Mojave (10.14.6) from the link here - https://support.apple.com/HT211683, as upgrading directly to latest not supported for this version.
Apple Store pops open and clicking Get asks for logging into Apple Store through iCloud account, which was skipped during upgrade time. Signing in gave this error: "Apple ID Verification Code Required: type your password followed by the verification code shown on your other devices." There was no code received and there was no other device. What are some options at this point?