When you first set up Two-factor Authentication (2FA) you'll have 10 recovery codes to use. If you've used a few codes and are getting low, you'll see a message like the one below to advise you should generate some new ones.
To do this, select 'get a new set' within '2FA' on your account.
You should then see a screen, similar to our test example below, with your own new recovery codes generated.
Save a copy of these codes and store them somewhere safe. If you lose access to your authenticator app, you can use your single use recovery codes to sign in to your account.
Please note: without these codes you may lose access to your account.
If you've used all your recovery codes and can see a message like the one below in your account, you'll need to generate new codes as soon as possible before you can log in again using the recovery code method.
Select 'get a new set' and you'll have 10 new recovery codes generated.
As per the advice above, save a copy of your codes and store them somewhere safe.
If needed, two-factor authentication can be accessed from your account profile screen, which you can get to here