Actually, Zebra did not provide direct driver for ZM400 Printer on Linux OS and even for MAC. This is a kind of bar code label printer. Only one way to configure cups to install / run the same printer on Linux OS. See the Zebra recommended Procedure, when the page comes on the browser, select the printer model (by scrolling down and you see the name ZM400), select it and then click “SUBMIT” button. On next page, look for “Third Party Drivers” and click download, on next page (most probably new windows / new tab), click “ACCEPT AND BEGIN DOWNLOAD NOW”, it asks to download a PDF file, just download it and minutely read the file which helps you to install the same printer.
For your better concept, see the Label Printing – Linux OS. Though it is based on Ubuntu OS, but it may apply almost all Linux OS, only the syntax may vary.