I don't see that option anywhere.
it is new to 8.1. Are you running 8.0?
I don't see that option anywhere.
No, I have 8.1.
On your iOS device there is now a Settings > Messages > Text Message Forwarding section.
Iphone 6, iOS 8.2
I don't have this option in settings. Is it because I don't have Yosemite installed? How would my phone know this???
I don't see that option anywhere.
I tried everything posted here but nothing worked. Reset iMessage a heap of times on all devices. Made sure they were all setup with the same phone number and email address and I still wasn't getting any codes.
In the end, I reset my iPhone 6 by hold the home and sleep/wake button until the apple logo appeared and then disappeared again. Only then did I let go of the buttons. The iPhone rebooted and only then did I get the code on my Macbook and iPad.