This is all I do. I’ve got my Bolt here now so this is what I click on.
Register with https://ridewithgps.com/ it’s free and great for this sort of thing. Plan and save a route on there (I use a selection of the map views when plotting one and make sure ‘bike paths’ is selected to help too). You could just search for existing routes instead if you wanted.
Download the Elemnt phone app and scan the qr code on your bolt to initially connect them. Make sure Bluetooth is on on your phone and when they are connected set the Bolt up on your wifi.
In the app select ‘settings’ and ‘automatic upload’ (under wifi). From here you can link your Bolt to many other websites or apps, mine is linked to Strava and RWGPS so after every ride the route and stats are automatically uploaded to those sites.
On the Bolt click the third button under ‘page’ until you get to the maps page. Here the first button lets you select ‘route’ click that and it shows you any existing routes and when you last ‘synced’ them to the Bolt. Click the middle button under ‘sync’ and it connects to wifi, syncs with Wahoo and any linked accounts (this copies the routes onto the Bolt). It will show ‘synced all’ when done and the routes should be listed. Use the buttons on the right hand side to scroll through the routes and click the middle button when on the one you want (it says ‘select’). The route is then loaded and the centre button gives you the ‘start’ option, click that and peddle away!
That should work. I think it’s great, I’m impressed.