If you're familiar with creating and managing cases, then you may want to invoice for appointments directly from a case.
The appointments table in cases includes the status of the appointment, so you can see at a glance whether appointments were marked as arrived, not arrived or cancelled.
After adding appointments to a case, you can click the plus icon to add an appointment directly to an invoice, which will auto-fill the invoice ready for creation in one click.
And when an appointment has already been invoiced, you can click the invoice icon which will take you right to the invoice with the supporting activity.
That is how you quickly invoice directly from a case. If you are looking to quickly create invoices for supporting activities in a case, (although the same process), you can check out the help guide.