1. One problem that exists using Apple products is that when your product is downloaded you must print from the browser without closing that browser session. Once the browser session is closed, one can no longer access the product. This is because Apple products do not allow access to a download directory like Android or Microsoft products.
2. I believe iPhones/iPads use AirPrint to print from the browser.
3. Use the AirPrint app to print your downloaded product.