post
https://api.ecartapi.com/api/v2/orders//fulfillments
Creating a Fulfillment in Tiny
To create a fulfillment in Tiny, you’ll need the tracking.companyID value. You can obtain it by making a request to GetCarriers.
If you want to add a shipping method, you’ll need to use the fulfillment.shippingMethodId value. To get it, make a request to GetShippings.
The shippingMethodId field is optional and can be omitted when creating fulfillments.