How to connect gravity forms to mailchimp
Before you connect your form to Mailchimp make sure you have a Mailchimp account activated. See this article on How to Create an Account on Mailchimp
To connect Mailchimp to your form Open your form -> Settings -> Mailchimp
Then click on ‘Mailchimp Settings’ to configure Mailchimp.
Then put you Mailchimp API in the ‘Mailchimp API Key’ field. Then click on ‘Update Settings’ button to save it.