My App is Hosted at app Platform (Static sites) of Do.
These answers are provided by our Community. If you find them useful, show some love by clicking the heart. If you run into issues leave a comment, or add your own answer to help others.
To use a custom 404 page, you can generate a file named 404.html at the document root during the build process and it will be used by App Platform.
Alternatively, if you are using React Router and it renders its own 404 page, you can route all “not found” requests to index.html and then React can look at the URL and generate a 404 page if the route does not exist. To do this, navigate to your App -> Components -> select the static site -> Expand the “Custom Pages” section. There, choose “Catchall” for the type and enter index.html for the page name.
Let me know if that works!
With App Platform, you can: