Thank you for the clarification, mot-alak.
QuickBooks Online uses scalar Fields to fetch your company information. It's different from the one on the link you provioded. There are different variables you can use to customize your invoices. You'll want to download this document to see which ones are accepted: QuickBooks Online EZ Map Fields Catalogue. You can also use our samples.
Check out this article for more information: Import custom form styles for invoices or estimates.
Let me know if you have more questions.
