fontello not working

[Fikri Maureza]

hi, i use several icon https://github.com/cupof-github/several-icons , so i can use line logo

but i dont know where i should put <link rel="stylesheet" type="text/css" href="/several-icons/css/fontello.css">

and after following the fontello guide the icon didnt show, please help me, thank you

i am using one engine theme on wordpress with font awesome included