You will receive one of these emails after you have accepted the payment a group has submitted to you. If the payment submitted was the final payment and the purchase is now complete, you’ll receive the message with subject: “Final confirmation - Pay By Group completed”.
If the payment submitted was an interim installment, you’ll receive the message with subject: “Confirmation - payment sent for...” (which will include the actual name of the purchase and the installment stage in the subject line).
In either case you can click the blue “View group details” button in the email to navigate to the purchase’s dashboard in your business portal.
Follow your normal business practices for when a payment is confirmed and you need to fulfill the order. That includes sending any needed confirmation details to the group organizer. If you manually accept Pay By Group payments then you should take these steps when you actually accept the payment, rather than wait to receive one of these notifications.
These notifications are most useful if you auto-accept payments, or accept them via API, and then have to take one or more manual steps to fulfill the order.