I can't link a picture in my blog post to a lightbox/pop up. I can only link a web address. This is highly frustrating since I want my readers to be able to download freebies with opt-ins. So I need them to be able to click on a picture, this should shoot open a lightbox with a form asking for their email address, and after submission they are redirected to the freebie that they can download. But I can't do this, because it only allows a web address to be linked to blog post pictures.