What functionality is missing? What is unsatisfying with the current situation?

  I’m building a business around World Anvil and protecting my content is critical. I would love the option to turn on 2-factor authentication (2FA) in order to get into my account, as well as the ability to require my authors to do the same. 2FA is becoming more common on other cloud services, and there are may apps that make it easier for clients to use 2FA with little inconvenience (like Google Authenticator).  

How does this feature request address the current situation?

  Currently, accounts only require passwords for access. Having a second barrier for access would make access to my business critical content more secure.