Rates API

I have a question about this endpoint https://api.easyship.com/2023-01/rates. The endpoint documentation shows that you can pass either the ID or the SKU of the product, but I'm getting this error 422
{
"error": {
"code": "invalid_content",
"details": ,
"message": "The request body content is not valid.",
"request_id": "091b71a1d17b19f63b63317d71857e0e",
"type": "invalid_request_error"
}
}
the documentation states "if you provide the box object, its dimensions will prevail over the summary dimensions of each individual item. If not specified, items dimensions are mandatory to calculate the best box size for the parcel".
I don't have the box nor the item dimensions so I can't provide them, and so I want to know why I have to pass the item dimensions if I'm passing the ID/SKU of the product and the dimensions can be obtained using that ID/SKU.

With that being said I'm wondering if there's a way or something I can do to avoid sending the item dimensions of the product.

Thank you very much, I appreciate your help