If you lose access to your authentication app, you may use one of your recovery codes, which you generated when you set up MFA.
When presented with the screen to enter your MFA code, click on the Use Recovery Code button at the bottom right-hand corner. You will then be presented with the following screen.
Here, you can enter one of your recovery codes, then click continue. Please note that you may only use each recovery code once. Once you use a code, you should cross it off your list. You may generate a new set of recovery codes at any time by following the steps in this article.