How can I change form URL

Hi,

If you mean the custom URL, just please follow this guide: http://www.jotform.com/help/261-How-to-create-a-Custom-URL-of-a-form.

You can also setup a custom domain for your form: http://www.jotform.com/help/144-How-to-use-Custom-Domains-with-Jotform.

Thanks