Where/how to place/use "cinnamon-opacity-slider" ?

[echo vapor]

I found in this post:

• https://forums.linuxmint.com/viewtopic.php?t=391314 ,

a .JS script :

• extension.js ( https://github.com/NeatNit/cinnamon-opacity-slider/tree/main/opacity-slider%40neatnit.net )

To add an opacity-slider when performing a right-clic on any window bar.

I'm realy not sure how I must use it (something about Compiz ? A folder ?). Since the original creator havent gave a manual surely because it's "too much easy to understand", I'm here to listen all of you to know more about this Linux part. I dont find the good key worlds with google... Thx !

[wanton moth]

you don't really need it per se. Look in Settings, Keyboard, shortcuts. There's a keyboard shortcut to increase or decrease any window's opacity.