Amazon ask me provide invoice, but I am print on demand or dropship, how ?

I received message ask me invoices from supplies which enough for 1 year ssles.

But I am selling print on demand or dropship, how to prove for one years sales?

It provided a option said I am a dropshipper, but actually, I designed products and then pass to suppliers, not 100% dropship.

If choose this option, any impacts?