Double sided print option not available in dialogue box in Pages
I have Phaser 6510 printer. Duplex printing installed. Option in Pages for double sided printing not available. Double sided printing option in Adobe Acrobat Reader is available for same printer. Also, when printing from pages to same printer, Pages doesn't recognize bypass tray for envelopes and will print to that tray. Acrobat Reader recognizes both trays and both paper sizes. What to do?
MacBook Pro 15", macOS 10.14