HP envy 6500 printer doesn't recognize Pages
HP Smart App does not recognize the Pages app when asked to print a document from the HP app.
MacBook Air 13″, macOS 11.7
The app likely recognizes only standard file formats such as PDF, EPS, JPEG, and the like, plus some widely-used proprietary formats such as Word .DOCX. It's likely that it just doesn't know how to interpret a .pages document.
Your options are to export the .pages document to something the app does understand (e.g. PDF), or to print from within Pages, rather than through the intermediate app.