I have not had the need for this, so I have not played around with it.
But, is there any way you could render that text to an image?
Then you could print it with that print image command, right?
One solution might be to incorporate QR codes into the process... receipt data to QR code.
That way you could print out the receipts with the print image, since the QR codes are saved as an image.
There are many apps out already (and you can code it in AppGameKit too) to read the values/data of QR codes.
Not exactly the best idea for legibility of the printed version, but it should be a simple work around to implement.

Coding things my way since 1981 -- Currently using AppGameKit V2 Tier 1