Text Message Forwarding activation code
I am trying to setup Text Message Forwarding from my iPhone (OS8.3) to my MacBook Air (Yosemite). I am signed into iCloud on both and I've gone to the Messages Settings on my phone to turn on forwarding for my Air and it asks for an activation code. I then go to my Air and turn on Messages, but it doesn't seem to have a code displayed anywhere and I don't know how to prompt it to give me a code. I do have iMessages as an account with my Apple ID in the Messages program on my Air. One odd thing is that it doesn't show my iPhone phone number in the list under "You can be reached for messages at", although it does have my gmail and my iCloud mail addresses there. The only thing that can be added there are email addresses. I am thinking I need to do something to get my phone number to show up on this list so it can prompt Messages on my Air to give me a code. I can't seem to find how to do this. Or is there some other way to get the code from Messages on my Air to enter into my phone to approve message forwarding?
Thanks in advance!
iPhone 6, iOS 8.3