How I do it:
1. Click share
2: Copy link
3. Paste link in comments (Don't post a comment yet!) The link will be https: //imgflip.com/i/123456
4. Before "imgflip.com," add "i." making i.imgflip.com
5. Delete the /i, making the link https: //i.imgflip.com/123456
6. add ".gif" to the end