Well, these are the steps to install LiquidBounce 1.16.5:
LiquidBounce itself. Put that file to mods.
Fabric Kotlin Language. Put that file to mods aswell.
Fabric loader for 1.16.5. You run that file as it is for installing purposes, and just hit next all the way during installation.
Load your Minecraft launcher, select fabric-loader-0.11.1-1.16.5 and run the game.
Profit, I guess.
EDIT: And for click GUI, just type .bind clickgui <akeythatyoupreferhere>. Trust me, there is nothing good to see for now.