Yes, this is possible, Howard.
I've got you covered. I'll provide the accurate steps to set a different default template for your invoice and sales receipt.
Once you add and customize a specific template for each sales transaction (invoice and sales receipt), we can set it as the default, so it'll automatically apply to all entries when you create them.
To do so, please follow these steps:
You can view the screenshot below to see how they'll appear after you have performed the instructions.
For more details about personalizing and adding specific info to your sales forms, please see this article: Customize invoices, estimates, and sales receipts in QuickBooks Online.
Finally, you can start creating your sales transactions without updating the template constantly.
Do you need additional assistance with the process, Howard? If so, please don't hesitate to get back on this thread. I'm always ready to help you out. Aside from that, you can also post other QuickBooks-related questions and concerns. We're open 24/7.