Under iMessage settings there is no text message forwarding
I am trying to setup text message forwarding, as per this support article:
https://support.apple.com/en-gb/HT208386
However, on my iPhone, Settings, Messages, there is no "Text message forwarding" option listed.
iPhone XS Max
iPad Air
The "Reachable At" phone number listed on my Apple ID Account settings is that of my iPhone.
iPhone XS Max, iOS 13