I do not quite understand how to set it up.
It already fails because of the following:
Login to your printer settings using your printer Terminal Id here.
Where do I find the Terminal ID?
The printer’s manual is not really helpful.
see here as a starting point i would suggest https://www.youtube.com/watch?v=Heolni3WnX0
if the printer manual is not helpful , you need to contact goodcom directly. after all, it’s their printer (and it may even be different for each of their printer models as to how to access those settings …)