What is the format and sample of the invoice?
You can try to type it out in white paper first, and then print the invoice after debugging. Click Print when debugging, and there will be left (right) tone and up (down) tone. Fill in the blanks, try to print, generally adjust 2 mm. Print a ticket with white paper, put a blank invoice on the back, look at the light, then print it, and adjust the distance left and right until everything is in the invoice.