How do I get my Order ID back on my Receipt/Invoice?

Got it. You can setup the Receipt by going to E-Commerce Setup > Receipts this will send the Order Number

If you are sending the Invoice after purchase it does send the Order # even though it’s titled as Invoice#
E-Commerce > Settings and then click on Orders from the left side menu > Email Invoice upon successful payment


These currently are the only areas that the Order Id can be sent.