Help with setting up icons in nvim

I want to add icons to my neovim configuration, but I am still not able to get some of them working. To give context: I use Artix and urxvt(which i have compiled through the AUR with pixbuf support) as terminal. For font I use the “hack nerd font” and it DOES support icons.
Now, the problem is that even though I have read and walked through the guide, some icons still don’t appear. My config looks like this:

set enconding=utf-8

call plug#begin()
Plug 'preservim/nerdtree'
Plug 'vim-airline/vim-airline'
Plug 'vim-airline/vim-airline-the,es'
Plug 'ryanoasis/vim-devicons'
call plug#end()

At the moment only a select few icons are working(folder, pictures and text icons, to be precise).
I’ve got no idea what to do, so any help is greatly appreciated.