Intel ARC Gpu configuration

[Host-in-the-Shell]

What OS is your server running? I'm assuming from the document you linked that it's Ubuntu; in that case, you should follow the documentation in order to ensure that the card is set up properly for Jellyfin. And yes, you're going to want Quicksync, and also to select the right codecs under your server dashboard > playback > transcoding. Here's the info provided by Intel for video codecs supported.
By the way, the same document you linked states that

Starting with Ubuntu Desktop* 23.04, the full range of Intel® client GPUs is expected to work with the default Ubuntu installation, except for GPU debugging features.

So if you're running an older version of Ubuntu, an upgrade to a newer version can go a long way into improving the overall compatibility with your card and you can do away with all these annoying installation steps.