Product Update File - This is used add more attributes to products

From the import type dropdown select Product Update.

5C9894C8-3685-4C00-B4A1-84A0D57228E4

You can see the required format by choosing this button

246746A3-7B7A-465A-BF9E-6DD1092F3285

95ABB60E-97C5-43A4-9756-191860A18DC2