Not able to map all the product variations fields in commerce feeds importer

Hi,

I have one content type and added one field Product Variations' as product reference with widget 'Inline entity form - Multiple values'. But when I used Node Processor, I am not able to map other fields of the product variations. It only shows SKU and Product ID fields in target drop-down. It shows all the fields from node but not from the product variations.

Because of this I am not able to add more fields in my CSV file except title and sku.
Does anyone have any ideas on this?

Thanks