I have Facebook login approvals set up. Is there any way to stop Facebook from sending login codes via SMS? Preferably, I'd like to exclusively use my Google Authenticator app to receive login codes.
I use MightyText to sync my texts to my computer (and their servers), and therefore my login codes get synced as well. If MightyText gets hacked, it could jeopardise my 2 step authentication.
Edit in response to answer: After disabling and then enabling facebook's login approvals, I still receive text messages. There doesn't seem to be a way to remove text messaging as an option. 
Best Answer
You can switch to Google Authenticator based code generation from Security Settings → Code generator menu.
Click on Set up another way to get security codes, it'll guide you to setting up Google Authenticator for code generation