You can. We offer a free, branded version that we encourage students to use for their school projects. You can access the library here.
Keep in mind that free users agree not to remove, hide, or reduce the visibility of the ZingChart branding (watermark and context menu item) per our branded licensing agreement. For questions, you can always reach out through our support chat (see the bottom-right corner of the page) or by sending an email to firstname.lastname@example.org. Support hours are also available for purchase on our Buy page.