Unable to use images in my signature

[ElijahHouck]

Hello, I've tried a million different hosting sites, different resolutions and filetypes on my photos, but nothing I've tried has let me upload images in my signature. This is the BBCode I'm trying to use:

[url=https://forums.nexusmods.com/index.php?/topic/9299888-wip-a-better-world-upcoming-huge-new-world-and-quest-mod/][img=https://i.imgur.com/Rwj6hn1.png][/url][url=https://www.nexusmods.com/fallout3/mods/16949/?][img=https://i.imgur.com/hsAZTiC.png][/url]

And this is the error I'm getting:

 

 

Could I get some help figuring out what's going wrong here?

 

And as proof the BBCode actually works: