At the top of the GFY /post / reply box, theres a little icon its yellow with like a mountain and a sun on it. Click it and a box pops up. Pate the link you used
https://imgur.com/8gBvHOm and add .jpg to the end, so it says
https://imgur.com/8gBvHOm.jpg in the box.
Click OK... Jobs a good un