Well after much trial and error I found somewhere to put my kml file. See bottom right of screenshot. However these are not showing up on the map. Just had a thought these are named markers and the dialog in the boxes seems to be expecting a linear trace. So my question is are named markers supported and if so, having imported them how do I get them to show up?
Although Im not looking at the public version of the Editor, this is my process for displaying markers. Also, I have my editor window layout different to yours with most detail panels on the left as tabs next to the 'Place Actor Tab' you have. In the Content Browser, navigate to the folder I want the marker file to be placed. Click the green Add/Import button. Choose my KML file (containing both lines and markers). In the main window, change to Route Building Mode (Shift+7). Select Use Guides (Ctrl+Alt+G). Expand the KMLSource section and add an entry using the + symbol. Select the imported KML asset. Ensure there is a tick in both the Show Route Guides options. I set my width and height and distance to 0.1 / 300 / 4 respectfully. Under Guide Settings ensure there is a tick in Show Placement Guides. Hit the Use Selected Assets and Show Guides buttons at the bottom of the window. Additionally, next to the GoogleMaps button in the 3D window is what looks like a Check List button Click that and the named markers appear in there as Jump To points and on the Route Map (bottom left in my screenshot)
when placing track to my route I use my google api you can your api key following these instructions Setting up API keys - API Console Help (google.com). once you have it in the editor there is a google static maps drop down enter your api key there and in the overlay section make sure enabled box has a tick in it
Just an update, must be doing something wrong as despite following Adam's instructions I still couldn't get markers to appear. So going to give my brain a rest tonight and start with something fresh tomorrow.
Going to have one more attempt shortly. So far as the markers are concerned was wondering if like MSTS the editor is confounded by certain characters, e.g. _ underscore in lieu of a space or an actual space in either the title or entries.
Well knock me down with a duster. That seemed to work. Went through my Bermuda Railway kml file, knocked out all the _ entries and in the title and it shows up. However there is still a caveat. How do I get the markers to sit on top of the terrain rather than at sea level? But this is significant progress after my utter frustration yesterday.