How can I stop Facebook from saying that the link to my form is unsafe?

I recently made an order form for the books and CDs that I am selling through my FB. A prompt from Facebook keeps popping up that the link to the order form is unsafe, and I have to finish one of those tests (e.g. ,check which photos are those of cats) to verify that I am human. 

Can you please try sharing the form using the link below?
https://www.jotform.com/61793810530454 

Facebook requires any link or URL or content to be in secure mode. So when sharing links, it should always use the secure https protocol instead of the regular http only. If facebook detected non-secure content, it will have a pop-up security warning on the browser pertaining to the non-secure content. When sharing a form URL to facebook, please make sure to use a secure url.

Alternatively, you can also share your form to facebook page by following this guide: Adding a form to your Facebook page.