Hello @NamTruong2001. I'm a couple levels below that so I'm not quite there yet but from your screenshots I'd say you need a lot of fishes in this level.
Hello @noranora81 and welcome to the community! Whenever a player disconnects from the game whether deliberately by exiting the game or if the internet connection is lost on their end, you'll see it as them having left the game. I hope this helps!