To see how to 'Get a verification code and sign in with two-factor authentication', click here --> https://support.apple.com/HT204974
- Use a Trusted Device: Mac, iPhone, iPad, Watch. Code is either generated automatically or manually using Settings on the Trusted Device.
- Text or phone call to a trusted telephone number (any telephone; even landlines).
- Get a code from an Account Recovery Contact --> https://support.apple.com/HT212513
You might have to upgrade iOS in order to use the last method.