To import your customers into JRNI, you will need a CSV file of your customers.
Download the template here, and enter your customers. Enter the email, first name, last name, phone number, etc... The reference can be left blank, and the User Type column can be either Contact or Member.
Save your CSV file. In JRNI, click the Customers tab, and click Import. Click Choose file and select your CSV file, click the green Import button.