I installed the plugin mailchimp but can not find new users added on mailchimp

Do you mean to say you have integrated your form to MailChimp? Here's a guide for this https://www.jotform.com/help/163-How-to-Integrate-with-MailChimp.

Once you have integrated your form to MailChimp, a copy of form data should go straight in your mailchimp list on every form submission.

I suggest to review your mailchimp configuration and check which list you have set the data to go through so you can find them in your mailchimp account later on.

Example:

If you have further questions or if you come across any issues, let us know here.