custom field value for variants

-- HikaShop version -- : 6.5.1
-- Joomla version -- : 6.1.2
-- PHP version -- : 8.3

hi
i have several products and variants.
I also have a custom field called seller percent
celler percent field is filled for all main products, but not for variants. i want to set the value of this field for variants, equal to its parent main product