Google Merchant Feed

Hello,
How’s it going?
I have added several products to Google Shopping, thanks to the feed generated by webflow to have it in Google Merchant.

My products go in boxes and it depends on each box, there are 10 or 20 products. In the PRICE field of each product, I put the total price of the box. And I have a custom field in which I put the price of each unit, not the whole.

For example:
-Product 1. Price $ 209. Box of 10 units. Price per unit: 20.9 €

The Feed that Webflow sends takes the total PRICE, when I would like it to take the PRICE PER UNIT.

Anyone know of any way I can tell the feed to take that value?

Thank you