To export your JRNI customers to MailChimp, you first need to connect your MailChimp account to JRNI, to do this:
Login to your MailChimp account and find your API key.
Click the Cog/Settings icon.
Click Config in the Mailchimp box.
Enter your API Key and the default MailChimp list you wish to export customers to.
Your MailChimp account should now be connected to JRNI.
To export your customers to MailChimp:
Go to Customers.
Click Export to MailChimp in the left-hand column.
Enter the name of the MailChimp list you wish to export your customers to (if different to the default)
Select Export to start the export.
Once the export has completed, a notification will be displayed and MailChimp, the exported customers will now be listed.
Note: Each time you perform an Export, it will only import new customers that are not already on your MailChimp list.