From the left main menu, click on your Username, then select "Account" in the flyout menu.
From the account page select "Extras", "API Keys".
Your API Key will be listed in the table labeled "Your API Keys". Copy / Paste your API key into the MailChimp Module2 setup.
Click on the Audience main menu item, then click the Audience you'd like API users to subscribe to. In the "Manage Audience" dropdown, select "Settings".
Scroll down the bottom of the Audience settings page to see the list Id (labelled "Unique ID for audience". Copy it from the textbox.
Click "Campaigns" from the top menu. Scroll down to "View by Type" and click "Automation"
In the dropdown click "Edit".
Click "Pause and Edit".
Next to the trigger text, click the "Edit" text link.
Copy the full link labelled "A subscriber's email ID is posted to the endpoint:"