I am a developper who is maintaining a shopify app that makes use of the carrier service to get rates at checkout.
A lot of our customers who are using the app have been asking why we don't make use of their package dimensions when creating our rates. As far as I know from what I have read from the API docs, the carrier rates webhook information doesn't send package dimensions. We have been asking the customers of our app to use the dimentional weight for their store items to get more accurate rates from us to compensate for this problem.
Is there some way we can access a store's packages such as shown in this page:
Are these features only availble to be used, or is it something that is exclusive to the carriers listed in the same page?