Q: text message forwarding iphone 7

So this was working for me, and when I set up my iPhone 7 text message forwarding to my imac (el capital latest version) is not working. Also there is no menu option on my phone for text message forwarding as described below:

Set up SMS and MMS with Continuity

1. You need iOS 8 or later on your iOS devices and OS X Yosemite or later on your Mac.
2. Sign in to iMessage with the same Apple ID on your iPhone, your other iOS devices, and your Mac.
3. On your iPhone, go to Settings > Messages > Send & Receive. Add a check to both your phone number and email address. Then go to Settings > Messages > Text Message Forwarding and enable the device or devices that you want to forward messages to.
4. Look for a code on the Mac, iPad, or iPod touch that you enabled. Then enter this verification code on your iPhone.