Young Sheldon: S04e18 720p Webrip

(or .mkv )

Based on the pieces you provided, here's the correctly formatted version: young sheldon s04e18 720p webrip

It looks like you're trying to form a proper for Young Sheldon S04E18. a common example would be:

If you need a more complete scene-style name (including source group), a common example would be: young sheldon s04e18 720p webrip