After you enter your Sage account login details, if you've set up 2FA, you'll be prompted to enter a 6-digit code.

TIP: The app won't send you a notification automatically; you must open the app to see your code.
TIP: If you're using a private device, you can select the Remember me on this device for 30 days option. 2FA isn't required for 30 days after you select this option.If you don't have access to your 6-digit code, for example you've lost your phone, or you're not receiving codes, then you can use your recovery code or recovery method.
For more details, visit I can't authenticate using 2-factor authentication (2FA).
If want to change the way you authenticate, for example, use an Authenticator app instead of text, you can easily do this.
For steps, visit our article Change your 2-factor authentication (2FA) device.