>>>Your legal company name, like XYZ enterprises and you will be getting GST with that only. In case of proprietorship no need of unique name but in case of PVT LTD, LLP etc your company name should be unique. On amazon you need to specify company legal name on amazon setting pages.
Amazon display name – On amazon product page, it will show your company display name which you can keep same as legal name or you can also select a different name like “Super Hot Deals”. If you want you can keep display name same as legal name like xyx enterprises.