accepting account book buy happens money payment paypal requires send sign thank-you try website

Hi, when I go to my website and try to buy my own book via Paypal, it requires me to sign in to my Paypal account, but when I do it says "You can not send money to yourself". How come this happens? Thank you for your time,

To buy your own book, you need to use a different PayPal account than the one where you are accepting the payment.