Signature help?

I wasn't sure where to post this, so if it's a wrong location feel free to move this

I recently bought some cute sprites from deviantart, and I hear you could use them in your signature. I tried using these things [/img] but as you may see in my signature currently, they just show up as if the link I posted was broken.... although I did try several things. OTL

I'd like to ask for help with this ^^'
here are the sprites: fanicom.deviantart.com/art/C-Irene-Kazuo-536471846