After payment has been made, you can view the receipt by clicking the "Finances>Invoices."
Once on the invoice page, select the "Paid" button above the "Quick Customer Search" bar to show the invoices that have been paid.
Find the invoice you want to view the receipt for and click the Magnifying glass for it.
You can see the amount paid and anything that's still due for that invoice.
From the "Send" dropdown, you can send the receipt via Email, Text, Regular Mail, or copy the link.
From the "Mark As" dropdown, you can also mark the receipt as sent by either Email, Regular Mail, Text, Dropped Off at Property, Not Sent, or Mark as Written Off.