I want to put the gps Lon, lat on the transmitter telemetry. However I don’t see option for it in the telemetry display. I know it’s possible because someone wrote about it. Just can’t find it. 
System
Frsky Horus x10s exprese
FrskyOS
Receiver
Mx r9 ota

Thanks for any help, I know most of you have moved off frsky so crossing fingers!

How about just using a simple LUA script: https://github.com/moschotto/OpenTX_GPS_Telemetry

I How about just using a simple LUA script: https://github.com/moschotto/OpenTX_GPS_Telemetry
I edited the original post. It’s not opentx.

Sorry I missed the bit about it not running OpenTX.

I do not own the same radio but I assume it does support OpenTX.

I am not sure if FrOS even supports LUA scripts.

I can't find much info online on FrskyOS but I assume it will have a Telemetry display option of using bars or numbers similar to OpenTX that you could use to display GPS coordinates on a custom Telemetry display screen.

That’s really been the problem all along with frsky. Got to be one of the worst documentation of any product line I’ve ever seen. Not many people use it and even frsky abandoned the FrsOS for Ethos OS. Now I wonder gee, do I want to put Ethos on my radio? Then there’s the scream that says noooooo don’t mess with the OS the old one works fine! I’ve played around with various data being shown in the boxes( alt, max speed, temps etc. I don’t see anything that looks like coordinates to be displayed. Boys and girls this is why you don’t buy your stuff after watching YouTube video stars!

I can understand the notion of “ don’t mess with the OS the old one works fine” but I am a tinkerer at heart and thats the first thing I do.

I usually start thinking about hacking stuff right after unboxing them and powering them on first time.

Any non OpenTX radio is a no go in this hobby. Even a closed source radio from ORQA did not get a second look by most reviewers or FPV pilots.

I agree. Time to ditch FrOS on your X10S and flash it with either OpenTX or EdgeTX. I've seen other people using that transmitter with OpenTX or EdgeTX on it with no issues. Once you make the jump you will be wondering why you didn't do so sooner.

Just back up all your current FrOS settings before you do that just in case you want to go back for any reason (which you hopefully won't).

Well that seems like a good idea. I’ve been using it for more than 2 years now. I’ll make that the next few weeks project. I don’t even know what a LUA script is so there’s going to be a little learning I’m guessing