When asked 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 of the 2FA activation process, or in the Two-factor authentication section found in the Settings Menu - Account security.
Make sure you back it up and keep it in a safe and easily accessible place.
How to log in with your backup code:
Log in with your credentials, then tap on the LOST ACCESS TO YOUR AUTHENTICATOR? button on the bottom side of the screen.
After you've tapped on the button, a window will appear from the bottom of the screen.
Enter your code, and tap Use backup code.
You've successfully logged in using your backup code.