When prompted for a 2FA code during log-in, you have the option to use your one-time backup code. This code can be found at the last step the 2FA activation process, or in the Two-Factor Authentication section, in the Settings. Make sure you back it up, and keep it in a safe and easily accessible place.
How to log in with your backup code:
Login with your credentials, then tap on the [LOST ACCESS TO 2FA CODES?] button on the bottom side of the screen
After you've tapped the button, a flyout will appear from the bottom of the screen. Tap on [USE BACKUP CODE].
Enter your code, and tap [CONTINUE]
Then write down your new code, and you've successfully logged in using your backup code.