Already did the "take a picture with a piece of paper..." thing and thought I was all g...

Already did the "take a picture with a piece of paper..." thing and thought I was all good to go. I have always been able to access my account via the web on my tablet (never lost that approval somehow), but anytime I try to access via my computer on the web, it says it needs to send me a two-step code to my phone, I say okay, nothing shows up on my phone. It then says an alternate is to go on your phone, open up Facebook app there and Generate a code myself...well, guess what the facebook app on my phone says...?! I need a code to log on via my phone!!!!! And when I tried to log on via the app on my tablet, same ****, different technology. So, one avenue works (tablet via web), but I'd like the app to work on phone and tablet and the web access to work on my computer.