Lost Font Awesome

I am trying to add social icons to my header, but when i use the syntax
`<i class=”fa fa-facebook”>
nothing appears: I can see the code in the html but it isnt’t traslated.
I am almost sure I accidentally clicked load essential Icons, but now I cannot find it anymore in the options (meaning that in the page of the options where it was, there isn’t anymore).
Using the free version (for the moment).

The page I need help with: [log in to see the link]