Hello and Welcome
First, let me make the most important point, Emby Server is fully supported on XPEnology systems running DSM 5.2-5967 or later.
If you're running an earlier version, check out the XPEnology forums for advice on how to update.
We've had many XPEnology users update without issue and there are members of the community here who will also help, just ask.
To reiterate what is detailed under Step #1 on the Synology setup page (https://emby.media/nas-server.html), pleas