2FA not working

When I click on tab that says to set up 2FA, a pop-up window arises with a QR code. The QR states "add verification code in passwords" then opens up my phone to "AutoFill Passwords", and says "to choose an account to add this verification code to". Box is not listed, and there is no option to add it. When I click, "view suggested authenticator apps", I am brought to a box support page titled "Multifactor authentication set up for your account". I then read these instructions:

1. Select Authentication App (recommended) and click Next.
2. Open the authentication app on your phone and scan the QR code. (You can also enter the secret key located under the QR code into the authenticator app manually.)

Under the second step, it states to open the authenticator app on my phone, however does not specify which authenticator app, nor does it give any suggestions to choose one. I already have two such apps on my phone for two separate electronic health records. 

I am trying to set this up for access to one of the (DrChrono), who has apparently now required this to access a necessary folder to run my practice. I have been through their support - no help. I am now trying support from Box.