Hello everyone
I might just give my opinion here and here is what i do for printing.
-Bought a Wi-Fi printer.
-Connected orders email to Outlook and there i made the following “rule”:
(When an email is received by <your orders email> play a sound and send to printer the order/email)
-The wifi printer autoprints the email

Things to bear in mind:
–You can always modify the layout of the email to your needs (hardcoding is required though or css maybe)
–Regarding the cost of the paper: From the printer setting i put it to print at 50% of the page. so that makes 4 prints of back and forth
— You can refill the cartridges instead of buying new and its really cheap

PS: My solution might be off topic but i think it saves the hassle of going through APIs of each GSM printer