To enable 2FA in FastPanel go to Settings -> Main -> Two-factor authentication:
A page with a QR code will open up. All you have to do is scan it with an authentication app of your choice and enter the verification code it generates in the textbox below the QR code:
After the 2FA is enabled, you will only see a textbox to enter a verification code if you wish to disable the 2FA:
On the next login, after you enter your username and password, you will be asked to enter the verification code from the app:
