You can pay a retainer fee or an invoice using the PayPal mobile app. It’s easy.
Open the app on your device and scan the QR code.
Enter the amount due and follow the prompts for secure checkout.
If you checkout with PayPal on a balance-due invoice after your report is finished, you may still get a reminder from Square payments about an overdue invoice. Please ignore these. I have to manually enter Square to close the invoice and this can take a day or two.