Hosting Images for Ao3

Okay, yes there are a billion threads on this in this sub, but some of the stuff is broken/outdated so I need recent help and data if that makes sense.

I want to post art for my fic in the chapter notes themself, but have ran into problem with trying to use a Tumblr link and following the AO3 instructions on the matter. It won't work for me for whatever reason, it just comes up as a failed image box.

Anyone have any tips on how to actually get art to show up on Ao3? ​​Tumblr and discord seem no longer viable, so I would love to heart alertnatives and/or actually get viable HTML code that allows for an easier image insert.​