MailChimp is a powerful email service provider. ManyChat + MailChimp integration allows you to add or update a subscriber to MailChimp to one of the existing lists.
Setting up an Integration
Go to Settings > Integrations and click Connect MailChimp Account button.
Connect ManyChat to your MailChimp account by entering your MailChimp login and password on a MailChimp page.
As a result, you'll see "Link email field" message which means your accounts were linked successfully (you can unlink them at anytime with Disconnect button). Now you have to select Custom User Field which contains user’s email to identify MailChimp Contacts.
To add or update contact in a List use the special MailChimp action in your Flow or Rule. Create an Action Step and select MailChimp Actions in a drop-down menu.
Select 'Add Subscriber to a List' Action and specify the desired MailChimp List.
Preview your Flow to make sure the integration works fine. As a result, you'll get a new subscriber in a chosen MailChimp List.