The API Key is the code that will allow your email captures to be added automatilcally to an email list in your MailChimp account.
Quick Video on how to find the API key in your account.
1. Click your profile name to expand the Account Panel, and choose Account.
2. Click the Extras drop-down menu and choose API keys.
3 Click the Create A Key button. Make sure to name your key, so you know which application is using the key. To change the label edit the text under the label column.
Paste the API link into the Email Capture Panel in the Builder and select the list you wish to add the captures to. Adding a List in MailChimp
