Java Script Not working

Site URL: http://www.jennydrew.com/bookbonus

Hello,

I wonder if anyone can help. I am looking to add a small bit of custom javascript to a section of one page of my website. It's just an email opt in box from Kartra. I tried to add it in, they told me I had to upgrade my package so I did when I went back the opt in form was showing up. I deleted it because i wanted to move it to another part of the page and now it won't work. Driving me mad, squarespace said it looked like incomplete code, can anyone tell me if this is incomplete?

<div class="kartra_optin_containerd3d9446802a44259755d38e6d163e820"></div><script src="https://app.kartra.com/optin/OlPouNLxbylF"></script>
 

Any help with this much appreciated!

Thank you SO SO much! You are a legend - sorted!!!