How to display the article in the invoice in the printed form in 1C-Bitrix?

Question

PHP

I didn’t find anything about Google on this question. The article is not in the invoice anywhere, and if someone asked, they didn’t answer anything, I’ll try to ask a question here. I found the output of the invoice file. The task is to display the Article. I put the "Article" in the product itself in the field ["ARTNUMBER"] how to write a code to print the invoice ??? remains a big mystery to me....