how can I shut down my jotform

Hi,

Are you referring on disabling your form? If so, you can check this guide on how to disable your forms: How to Enable Disable a Form. You can also set a form limit to your form to disable it depending on the date or number of submission. You can check this article for more information: How to Limit Submissions in a Form.

Do let us know if you need further assistance.
Regards.