You can't use imgur. It must be a site that supports https://.
These seem to work ...
- http://postimage.org
- http://imgsafe.org
/ipfs/folder in the link. )https://ipfs.pics (Note: you must include the- http://flickr.com (GIF images will not work here)
What is the '!' for? Does it have something to do with the alignment or significance of the image?