Using iPhone 5 (MD664LL/A) as an iTouch
I have an inactive SIM card installed in an iPhone five (MD664LL/A) and its connected to my WiFi network. I want to use this as an iTouch basically, but cannot sign into iCloud on the phone with the same credentials that work to sign into iCloud on my Macbook Pro iCloud account. I don't see anyway on my Mac to generate a security code that can be sent to the iPhone 5 either.
Why can't I sign into iCloud on this phone being used as an iTouch essentially?