Messenger started making it easier to pay your friends for dinner back in 2015 when it introduced the option to transfer money in-app with a credit or debit card. If PayPal has always been more convenient, though, you'll love this collaboration: Facebook and the payment service have teamed up to give you a new way to split the bill. You can access the feature the same way you'd pay with a card. Simply tap the blue plus icon and then tap the green Payments button to bring up the two existing options.