Step 1.
Login in to the website via the login button at the top of the screen.
Under the "Site Settings" menu, navigated to "Content > Editions"
Step 2.
You see a list of the editions currently available.
To add a new one, click the "Add Term" tab.
Step 3.
Enter the date of your latest edition in "YYYY-MM-DD" format.
Click "Save".
This edition is now available to assign to articles & other content.