Trying to have texts (NOT iMessages) forwarded from my iPhone to my Mac.

So I want to have text messages (SMS) automatically forwarded from my iPhone to my Mac. I'd call this syncing Message on the two devices, but whatever..

Apple Support says, “On your iPhone, go to Settings > Messages > Text Message Forwarding. If you don't see Text Message Forwarding, go to Settings > Messages. Turn off iMessage, then turn it back on. Tap Send & Receive, tap Use Your Apple ID for iMessage, then sign in with the same Apple ID used on your other devices.”

OK so far.

But at "Choose which devices can send and receive text messages..." I'm stumped. I can't get to the screen indicated, the one headed "Text Message Forwarding." Instead I see one headed “iMessage. You can receive imessages to an reply from ...” And my phone and email addresses are listed to be checked on or off. That's the end of my line.

What should I do? Thanks. Anne