How can I import package?

I’m using unity 2019.4.11f.
I want to use Effect in Import Package, but there is nothing in Import Package tab.
How can I use the Import Package?

If you hit control+9 then Unity asset store will be open and then choose the asset you want to use for effects download it. After that another window will pop up, choose the folders you want to import and click yo import button at bottom right.