

I’d personally use the web editor at https://www.openstreetmap.org/ Make an account, go to the zone you want to edit and press the edit button. Add a line and once the line is added you can add a type to it (you can check the wiki if you don’t know which one to use)
You can enable tracking on streetcomplete that will track your walk/bike/whatever and you can use that as a guide on the web app should it be hard via satellite (do note that this tracking is posted publicly).
Perhaps something to bring up on the forums to see if anybody has input on how to do this! I personally haven’t had such a bad case locally yet. But you’re having a great impact updating it as most likely people pass up on using OSM based services because of it, and by having it up to date it may encourage those people to switch in the future.