To integrate your MailerLite account with Instafreebie, go the top right dropdown menu and choose Integrations. Choose Instafreebie and copy your API key.
Log in to your Instafreebie account and go to the top right dropdown menu. Choose Settings and then Mail Service Integrations. Click Connect to MailerLite. Now all you need to do is paste your MailerLite key and click Connect.
Then click Select a list. Here you'll be able to select one of the pre-made mailing lists for your books that were automatically created in MailerLite.
And you're done! You're Instafreebie connection is good to go.