[/quote]
Binance Academy has written an article on how to top up a BEP2 wallet with binance, and in this article it is written:
"Why is a MEMO required?
A MEMO is required because the BNB deposit address for all users is identical. The MEMO is a unique identifier assigned to each account that allows Binance to identify a deposit and credit the appropriate account. "

https://academy.binance.com/en/articles/how-to-deposit