Fulfillment resource will be deprecated in 2022-07. How to update the order's tracking numbers?

[seanli]

Now that the fulfillment resource is getting deprecated, how do we use the REST admin API to update the order's tracking number from the fulfillment center?

We are currently using the fulfillment resource to do that: POST /admin/api/2022-01/fulfillments/{fulfillment_id}/update_tracking.json.