Im actually having trouble using image hosting to post pics as well. Ive tried Flickr Imgur and Google photos and I keep getting the little image icon instead of the pic. Does the image hosting sites privacy settings have anything to do with this?
weird. I just right click on the big image once it loads and copy url. imgur used to work fine but now i have to wait a while because at first I get a blob: url, then I get the actual url, and I don't know how else to copy the url...
In general, try to select a url that is not the thumbnail but the full size.
I use imgur or I used to use my own website. I'll have to put it up again. Using gitlab pages... don't know if they appreciate being used as an image host.. kind of complicated to use though. but free!