With Premium extension you are able to sync the subscribe form widget data, & Form Builder widget data with your mailchimp, Aweber, ConvertKit, Drip and many other accounts.
Form Builder Widget Integrations Setup
Edit your form builder widget and find integrations tab, Here you will be able to setup connection with email notifications, MailChimp, ConvertKit, Aweber and many more services.
Click on the accordion menu to reveal connection setup options for that service. You can use multiple services simultaneously with a single form.
Click on this link to generate the access token and paste it in access token field.
Once connected select your list from drop-down menu.