When printing from my iPhone to my HP printer, the paper size is stuck on envelope

Initially, I was unable to find a solution. I am not a computer tech. But I did discover that after downloading the HP printer app—I think it’s called HP Smart—I signed in and selected my printer. Then, in the app, you can manage your printer settings. I discovered that the tray size was selected as an envelope. I obviously changed this setting back to letter. I believe you can manage the tray paper size on the printer as well. I got the tip to use the HP app after calling Apple support. I was lucky to find a representative who had the same issue with his iPhone and an HP printer. He wasn’t sure how to use the HP app, but it was easy to figure out how to manage the printer settings on the app. Good luck.