Thanks for checking this functionality with the Community. I can share some information about the processing Paypal payments in Quickbooks Online.
At the moment, being able to use Paypal for online customer payments on electronic invoices is still in Beta testing. We are still working to make sure this feature gets available for your business use. In the meantime, I'd recommend sending a product suggestion to our developers to let them know about your product preference.
Here's how to send your suggestion:
Click the Gear icon.
Enter your feedback and suggestions.
Select Feedback for the Category.
Click Send message.
Your suggestion goes directly to our prestigious developers who consider feedback for QuickBooks enhancements. You can also check this website to know more about processing online payments in QBO: https://quickbooks.intuit.com/payments/
Please keep updated to our products feature release. You can contact me anytime if you need further help with QuickBooks. Have a good one!