The .fzip file is a Foxit add-on package format. It can only be recognized by Foxit applications. We could not double click to open the .fzip file directly, but we could install the .fzip file from within Foxit program.
Open Foxit PDF Reader/PDF Editor, navigate to Help menu, click on Foxit Plug-Ins then Install Plugin, choose the .fzip file and click on Install to install it.
For Foxit PhantomPDF Business or Standard, Please check here.