I am going to use easypost API for USPS shipping, and to use its pre-defined packages for example "SmallFlatRateBox" but I need to know its dimensions to count the package boxes of order items. But I can't find any method to get dimensions of pre-defined packages by their key names. Please guide me how can I get dimensions of pre-defined package?
Here is link of easypost API that I am going to use. https://www.easypost.com/docs/api
Thank you.