How do I create receipts for clients in Мy-dox?

In My-dox, a receipt is just a fully paid invoice. When your customer pays it (or you mark it as paid), the invoice will show

“Tax base: $XX.XX”

“Vat: $0.00”.

You can either re-send the paid invoice to your client, or just do nothing. The invoice gets updated for them so if they ever view it on their own it will be a receipt for them.