How can I add product dimensions in Excel for a bulk Shopify upload?

Hello. I’m trying to upload massive products in shopify via de excel bulk with these instructions:

https://help.shopify.com/en/manual/products/import-export/using-csv

All is good except I don’t see where or what column you define the dimensions (width, length and height) and unit (in or cm) if apply. As I manage above 1000 products Ineed to make bulk and all my distributors give me the excels with such information, meaning is not practical add one by one via the dashboard in the shopify that is why I need to make via de excel massively. I already have all the other information but to estimate a shipping correctly I need to enter the dimensions. I have large and small products then there is a lot of difference between products.

How can I do to add the dimensions bulk?

Or to ship via shopify is enough with the weight? Rare but maybe it is?

Thank you