Affiliate links not working

Hey, great theme here but I have an issue.

One of the post options allows you to add an affiliate link, I assume so that when you click on the image it will take you to the product.

I have tried adding an amazon affiliate link but it never works. I ma using the text only link and whenever I paste it into the box and update it, it disappears and the image is not linked to anywhere.

Is anyone else having this problem/has a solution.

Many thanks,