How to add "customer total order count" to opencart 3 Invoices

Question

I am using opencart 3.0.3.2. With the module in the link below, I can see the "customer's total order quantity" on the order page. but I want to see "customer's total order quantity" on the invoice page. How can I do this? can you help me?

That is, when we print out the invoice to prepare the order, I want to be able to see if the customer has placed an order before.