If your account manager has made two-factor authentication mandatory for the entire account, you will need to enable it on your profile as well. If you don't enable it, you will not be able to access any production linked to this that account.
NOTE: if you have access to other accounts where 2FA is not mandatory, that you will still be able to access those accounts.
If you try to log into Flow, you will see a blocked screen, such as the one below.
Click on the "enable 2FA now" button and follow the process as described in this article.
Alternatively, you will also have received an email that will also have this same "enable 2FA now" button. You can also click that button and you will be directed to the same process.