Great to have you here in the Community, @coreadviz.
Right now, the option to remove the Approved By and Date footer texts on the purchase order PDF is unavailable. As an alternative, you can leave the fields blank before sending it to your supplier's email. Please see the screenshot below to serve as your visual guide.
To learn more about managing your purchase orders in the program, I’m including this helpful article: How To Use Purchase Orders.
I’m here anytime you have other concerns, @coreadviz. Have a good day.