I am trying to add a hyperlink to the "append text to post

I am trying to add a hyperlink to the "append text to post content" section of a particular feed. Although I can add any link the actual link is corrupted due to the site name xxxx.com being added to the front of the link. Your thoughts?

I also tried adding an image with a link to this section too. The image would not display and once again the ink was corrupted as above??