A couple tricks I use to add just the click to show links inside Imgflip:
On my Windows PC, I left click and HOLD on the image I want to use, then drag the cursor to the comment box and drop.
On Android mobile, it's a couple steps. I click and hold the image I want to use, one of the options is "Open image in new tab". I go to that browser tab and the click to show link is in the address bar, copy and paste that.
The reason the links in the "share" button have the lengthy code (including links to the image page, imgflip.com and/or the Meme Generator page) is explained the imgflip.com/terms under Hotlinking