(Sorry, ignore my previous now-deleted response, it was for Strava not RWGPS!)
In RWGPS, go into the top menu, Jump To> Routes;
Select a route;
on the Left-hand side below the Name and route statistics, there's a big orange button: Export FIT File, with 3 dots on it.
Click the 3 dots > More Export Options.
You can select TCX or GPS from there, but your edge will accept the default FIT file too, so you don't need to use TCX or GPX anyway.