Hello mort1703,
Welcome to the Community. I'm here to assist you with any questions you may have with using QuickBooks Desktop.
Right now, the available form you can print and process in QuickBooks Desktop is P60. You can either order them from HMRC or reach out to them through this number 0300 123 1074.
Here's an article for additional reference:
Preparing and running payroll year end 2018/9 for QuickBooks Desktop.
For the P46(Car) and P11D form, you can download them directly from the government website. For more insights into the updated process, I'm adding the links I recommend on this:
Feel free to get back to me if you have further questions with your payroll. The Community will be around to help out.