On admin menu panel, please follow instructions:

Step 1: Click "Coming Soon"

Step 2: Paste Mailchim API KEY to "Mailchimp API KEY" field ( API KEY can be generated from mailchimp web site: Profile -> Extras -> API Keys -> Generate a Key )

Step 3: Click "Save Changes"

Step 4: The page will reload and new field will appear

Spte 5: Click "Enable Mailchimp"

Step 6: Choose which email list you want to use ( First you need to create at least one email list from Mailchimp web interface )

Step 7: Set what text will be displayed as title of the subscibe form

Step 8: Set what text will be displayed as a button title