However, the exchange is supposed to be anon initially, but of course the AO3 does not support fanart, and unlike the fanart-only anon exchanges I have participated in, chocolateboxcomm does not come with mod-provided temporary hosting. Normally I upload to my website, but of course my domain that would be visible in the URL is "ratcreature.net" so that would destroy the anonymity, ditto for dreamwidth image hosting.
I thought I could just upload it to Google photos temporarily, and set it to sharable, and eventually delete that and upload it to my website with a sig once the anon phase ends, but the share link that Google gives me doesn't get me the image, but some Google page showing it, that also shows my username.
So now I need to figure out, how I can anon host my image, so that it is embeddable but I can also easily delete it afterwards (because obviously I don't want the no-signature version out there permanently). And I also don't really want to have to create yet another account somewhere.