Make sure you are on Version 12.19.2 https://download.sterlingtrader.com/TrueEdge/TrueEdgeTraderPro64_12_19_2.exe
You can check if you are running 12.19.2 by going in your main True Edge Widget to Help and then click on About and it will show you which version you are running.
The first thing to do is make sure you have your Options Order Entry Box up.
If you do not have it up, in the main True Edge Widget go to windows and then Options and then Options Order Entry
Once you get your Options Order Entry Box up, to get to the stops, go to View at the top and then click on Expanded Order Entry Bar.
The Price Type box will enable if in the price box you have anything but MKT in the Price type box you will be able to select STP (Stop) or TSTP (Trailing Stop)
If you do not see STP or TSTP in your Price Type Box, Go back to the Main True Edge widget and go to View at the top then settings. Once in Settings on the left side hit Price Types and then make sure STP and TSTP are selected.
Here are some videos on Stops and Trailing Stops for Options: