My custom form URL won't open on my website?

So I've used the url on my website for people to register and make payments through jot form. But the link keeps saying this. I don't understand why this doesn't work but my other link to the other form works fine. Please help, i love jot form!!!!

You only have this custom URL: https://form.jotform.co/allentaua/12online not the URL on your personal training page. Please check and correct.

https://www.jotform.com/help/261-How-to-create-a-Custom-URL-of-a-form