What is this weird smelly metal sheet ?

It’s on the back of the metal sheet that holds in the keyboard on my Acer Predator Helios 300 laptop. The tutorial videos on how to replace the keyboard don’t have this in it? Is it just a coolant ? And if so what do I need to do to make sure I don’t mess it up.

It’s on the back of the metal sheet that holds in the keyboard on my Acer Predator Helios 300 laptop. The tutorial videos on how to replace the keyboard don’t have this in it? Is it just a coolant ? And if so what do I need to do to make sure I don’t mess it up.