Great question! I don't believe there is any option currently within Quickbooks that would allow you send an invoice with a PayPal payment option. That's something Intuit would need to integrated with the software using our APIs.
There was an older email tool we offered that may still work but it may not be supported any longer:
Something that I haven't tried yet is to see if you can include a PayPal payment link directly on the invoice in Quickbooks. You might be able to use a https://www.paypal.me link . The problem with that is you would still need to track payments manually to make if an invoice has been paid.
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