nopCommerce 2.0? Are you sure? That version is 7? years old.
Also, are you using regular multi-page checkout, or a one-page checkout? 3rd party one-page checkout?
If the customer has multiple addresses, then a drop down to select an address would appear.
I am using the payment process on one page
invoice address and shipping address appear, and I managed to deactivate the billing address but still appears when the customer is going to confirm the order