Can I switch back to previous invoicing format?

Thanks for taking the time to post your concern here in the Community, @seven89game.

Let me share some insights and provide some ways to help you with invoice formats.

QuickBooks Online (QBO) via browser and mobile app are the same software with different benefits and work differently with some features. 

With this, having the option to switch back to the previous invoice format is unavailable via mobile app.

In the meantime, I'd suggest logging in to your QBO account via a computer-supported browser for you to be able to edit an invoice and add a customer's payment.   

Furthermore, here's an article you can browse in case you need assistance receiving and recording invoice payments in QuickBooks Online: Record invoice payments in QuickBooks Online.

Let me know if you have any queries about managing invoices or anything about QuickBooks. I'll always be here to assist you. Have a good one.