Kanban-task-management-app build with react-router using localStorage

I used localStorage to save created board over page-refresh. It worked well while I was developing on my local machine. But there came up a problem, when I deployed to github. This is the issue: The id of a specific bord is part of the url-path. When I refresh the page with an id in the url-path it responses with 404 because there is no such path including the id on the server.

Any Idea how to deal with this issue? Thank you for your help or any other advice!