Do we generate invoice online or do we link ecommerce panel with quickbooks

Good to see you here, luxaderme. 

In e-commerce, a sales order or invoice may form the basis of a receipt. You might even package your products with a copy of the original sales order or invoice, to serve as the receipt. Then, link with your other accounts to help you track inventory.

Please refer to the articles below on how to create and send an invoice using QuickBooks. Then, how the system can show you how many customers you have in your company file.

• Create invoices in QuickBooks Online.
• Get the total number of customers in QuickBooks Online.

I'll be more than happy to help if you have any other questions. I hope my reply finds you with a smile. Have a fantastic day.

@luxaderme 

Which eCommerce platform are you using?