You can get a new xmitter with frsky telemetry built in from 3DR ,
the cost was a bit high for moi when I could get MAVLINK telemetry and GCS control(Tower App) on my android tablet instead with the provided equipment.
if you want to do it yourself?
you will need an frsky telemetry board and these instructions
I understand that the 9XR pro supposedly has this functionality built in(frsky telemetry capability) plus is considerably more capable of an RCTX and may represent considerable cost savings than from from the "official" source for modded th9x YMMV.. the xmit module from the th9x does directly transfer to the 9XR/PRO.
I did purchase a 9XR-Pro transmitter in addition to the X8R receiver. I wanted a transmitter with manual and more configuration options.
I used my leftover IRIS parts and build a frame to put the legs on. Add the Pixhawk and now flying it with the 16 channel receiver.
The telemetry screen in the pro is there but I couldn't see why I would look at the transmitter to get that info. About the only useful thing would be the battery level but I set a timer for that.
I use a tablet for most of the other functions.