After your topo image is uploaded you can draw lines on it to mark the routes.
Next to the topo image you just added, click "edit" and "draw lines". To draw the route, just click on its features on the topo-image.
You can draw already existing routes or create new routes and draw them too. You can also draw routes that are already drawn on other topo-images (given that they are on the same sector). If you make a mistake, you can click "undo".
To finish, click "save"