Integrations are available only for Engage plans
Go to the Site you want to configure data export for by clicking on the Site drop down menu in top right corner.
Once in site go to Settings by clicking the tab on left, and move to Exports section.
Select Export to mailjet.
Now click the Config button to open Mailjet settings, configure each field as below.
You can get the List id, Api key and Api secret from https://app.mailjet.com/signup
Don’t forget to Save the settings and click Finish once you are done.