Get selected pickup store informations with the API

We use Shopify Shipping to allow customers to chose a pickup delivery for their orders.
In our process, the company who takes care about shipping and creating labels for us gets the Order object with the API and use his informations to do so.
But, if the pickup delivery option is used, they don’t receive the selected pickup store type and id and get the pickup store address infos in the shipping address properties.
We need to get the pickup store type and id. How to do so ?