To integrate Mailerlite with ThinkQuiz, 

1) Go to Integrations >> Autoresponder Integration

2) Click on the arrow as shown in the image below.

3) Copy the API key from Mailerlite account and paste it in the provided field and click on Save button

To get the API key from the Mailerlite account, refer to the screenshot below,

- Now the Mailerlite account is integrated with the tool.

- Once it is integrated, then the button will be changed to Connected

To link the Autoresponder list to a campaign,

1) Go to My Campaigns and click on Actions as shown in the image below

2) Then click on Autoresponder,

Choose Mailerlite from the list (under API integrations) and then the list to which you want to send the customers.

3) Then click on the Save button. The autoresponder is linked to your campaign now.