When you purchased the Drop Ship Formula program you should have received an email containing this. However, if you do not have this, you can download one at any time by clicking the link at the bottom of this article.
After clicking the link, it will ask you for the email address you signed up with, enter this and then from the page that loads select "one time purchases" after doing this you will see your invoice and be able to download them.
https://dropshipformula.thrivecart.com/updateinfo/