Change artwork for files you've added to your favorites

Hello!
This is my first time using this community.
I look forward to hearing from you!
Also, please understand that some sentences may sound strange because I’m using a translation.

I use the iOS version of Infuse.
I want to add a Jellyfin file from my NAS from the “Files” tab and change the artwork of the file when it’s added to my favorites. I tried changing the artwork file name to favorite.png or folder.png, but it doesn’t seem to work.

Am I doing it wrong, or does it not work on iOS in the first place?

I’d appreciate it if someone could give me some guidance. Thank you!

This users guide may help shed some light on changing metadata

Thank you for your quick reply!
I read this user guide but it didn’t work so I posted it to the community. I tried changing the artwork file name to favorite.png or folder.png but it didn’t work. Is it difficult to set artwork for favorite files if you add files from Jellyfin on the NAS?