imgur won't work on this, or many other forums. You can either upload directly from your phone/PC/laptop, or use another hosting site such as Photobucket.
However, if you're on a laptop, its often easier just to upload direct. If you look below "this" section when typing a post, you'll see "Additional Options". From there you'll see the "Attach Files" section and "Manage Attachment" button. Click on that and upload directly
I tried the attachment earlier, however the pic size was to large. I supposed I'll give photobucket a shot. I used photobucket in the past but I recall the ads became intrusive and slowed the site quite a bit.