Host name

[nikkyseg 0]

What’s host name for lg 

[Neminem 1518]

You mean you have the Emby client and no server to link it to?

Did you install your own server, with your own media, on your own hardware ?

Your options are 
(1) install a server.  
https://emby.media/support/articles/Quick-Start.html

(2) ask a friend who runs a server to let you use theirs.

(3) access an illegal server (no further instructions here).

If someone else's have a talk with them.

Emby does not host your server and do not supply media files.