Problem with getting 2 factor authorization working in Authenticator

Hi Folks,

I'm trying to set up 2 factor authentication on my account/programs. I have the app downloaded on my iphone and have pulled up the appropriate screen on the desktop mac.  On the desktop, it tells me to scan the Q code on the screen by the iphone camera within the authenticator app.  When I try to scan, i get an error message, "Unable to register".  The desktop screen also says that if the scan does not work, to use a printed key code on the screen to enter into the mac.  Problem is that there is no place on the iphone app to enter the key code (it stays in the initial one and only screen it has shown me) and so there is no keyboard screen on the iphone to enter the code if I could.  Anyone familiar with this issue and is there a workaround/etc. that can be used?  Thanks very much, PATHOS25