Avoiding 404 Error on Page Reload with url_base_pathname set

The Multi-Page Apps and URL Support page provides an example of a multi-page app that starts with the code below:

When I run that example as written, I am able to successfully refresh the pages of the app, such as Page 1 and Page 2, with my browser.

If I change the app = dash.Dash() line to app = dash.Dash(url_base_pathname=’/app’), I am no longer able to refresh the pages of the app. I get a 404 error when I try to refresh them.

If I need to set the url_base_pathname to something other than “/”, what changes are needed in order to restore the ability to reload pages?

Thank you.