File rules allow you to map a file from a File Library to any path on your website. You can find this setting on your Site Settings under "Files".
To map a file to a path on your website, you must first create a library and upload your file to it. If you already have your file in one of your libraries, you can continue with this guide.
There are only three settings: "Path", "Library" and "File".
The "Path" setting determines at which URL your file should be available, relative to your domain. You can include the file extension or omit it. You can also enter a nested path such as /files/images/user.png
In the "Library" and "File" settings, you first select the library where your file is, and then the file you want to map.
Common use-cases:
Hosting domain verification files for AdWords
Hosting mobile app deep link mappings
Uploading custom HTML, CSS, or JS files to extend the functionality of your site
Once you have clicked on "Add File Rule" your redirects will not become active until you publish your site again.