Fenix 6 Solar - Round Trip

Assuming you mean creating Round Trip Courses on the watch...

Go to the relevant GPS activity, Settings for that activity, then Navigation. Scroll to Round Trip Course

This is where I'm getting stuck.  

Run - Navigation

My options are then.....

Back to start, Courses, Activities, Saved  Locations,  Sight "N" Go, Coordinates, Save Location.

I'm seeing that others are able to select a round trip route and are then able to selected an offered route. I don't seem to have this setting anywhere ?

You can create a course in Strava and then find it in Navigation/Courses. That’s what most people do.

Yes,  that's possible.  The idea of this feature though,  is that garmin makes a route for you for a chosen distance.  This means that it mate take you on routes you wouldn't normally run. 

Ah,  that's a shame.  To be fair it's not something I had planned to use.  I happened to see a video on it and thought I'd try it.  If it's not available then it's a shame,  but I'm sure I'll cope. Thanks everyone for your help

Oops! Missed that it was a solar not a solar pro. Sorry for misleading you 

But you can create in Garmin connect mobile a roundtrip and send it to your device (gcm>training>create course>…).

Just been looking at that.  I'll probably give it a try this week.  My problem is that I'm finding myself running the same routes all the time and it's getting a bit mundane.  Something telling me where to go,  with the potential to discover new areas is very appealing

No worries Phillip