I already have the UPC code from US1 .Do I need put the ASIN or anothe code on the product beside UPC ?
I assume you mean gs1. If your are only selling the product on Amazon, normal recommendation is to put the fnsku on it.
You need the UPC to list the product, but yes as @JwsMarket said, use the FNSKU on FBA products. The FNSKU number identifies the product as being yours and helps prevent commingling.
OK thanks u so much for helping me .I appreciate it