Tempalte to print fixed amont

Hi there
just wondering how to print a fixed amount on the bill, which was given as coupon on an earlier bill by a fixed percentage.
Result maybe like this:
*** RECEIPT ****
80000 Munich
Kleine str 82

2 coke 6.00
2 fajitas 14.00

Plain Total 20.00
Coupon discount 4.00
TOTAL 16.00

 HAVE A NICE DAY

discount may be never the same because it’s calculated and printed on an earlier receipt

thank you in advance

a fixed discount will do the job lol

But seriously you will want some way to automate.
Simplest way would be to embed the discount value in the coupon number/barcode.
Probably want to work out a way to prevent multiple uses.

Thanks a lot. changed to fixed discount, but the template prints only when calculated (percentage). the total amount is correct, but nothing to see on the bill .

Cant help without your template.