I can imagine your frustration on this. Please note that the notification option is available when you making the transaction on the new updated version of the app, you will be able to share this when making the payment but once the payment is done you won't be able to share the notification. The part of sharing the notification after making this transaction is the part that is still in testing with the development team. We currently don't have the specific date of the release but we will communicate this with you.
Let me know if you need further assistance on how you can share the notification when making your on-line payment.