You can attach them here at GJ or use a photo hosting website.
You're trying to use Imgur and that's an issue. The work around used to be dropping the "s" from the https. However that doesn't seem to be working any more.
Imgur doesn't allow links to work on sites that sell items, like 3rd party. Garage Journal, having a classified section fits into "their" category and it's why pictures are working here.
