Fonts Awesome not show

Hi, I′m testing the theme but I have one trouble…. when I try to put, for example…. in service part the font awesome icons, don′t show this icons…

example: fa-telegram-plane not show
fa-tools not show
fa-ethernet not show
fa-ad not show

How I can do that this icons appears??

For example, I tried fa-wordpress and it shows… fa-desktop also show

Thanks!!