To make payment. Invoice via PayPal or via email from seller?

[xjfan]

To pay seller for item, must seller send invoice via PayPal? Or can I receive invoice via email from seller, then make payment? Just want to make sure my purchase is protected.

[kernowlass]

@xjfan 

https://www.paypal.com/us/smarthelp/article/when-i-send-a-paypal-invoice%2C-what-payment-methods-can...