Post Processing Stack Issue

Hello there, i’m new with Unity, i’ve a problem with Post Processing Stack, version 2.1.3
Unity Version 2018 3.6.f1

As you can see in attached file i cant use effects… they are disabled.
It’s a new unity project with a plane and a character inside.
Where i’m wrong?
Thanks

What’s it say when you edit your post processing profile you are using?