Do State Name Short on contact via integration API

I use the API to create a contact and set its billing address.
I want to set the short state name, but keep automatically converts it to the full one.
How can I keep the state name short?


 addresses = new List<object>()
                    line1 = model.AddressLine1, 
                    line2 = model.AddressLine2,
                    locality = model.City,
                    postal_code = model.ZipCode,
                    country_code = "USA",
                    region_code = $"US-{model.STATE}",
                    field = "BILLING"

Good morning!

I’m not sure if this is a question regarding your framework, or the API? It looks like, if the select dropdown is populated with all the state names as its values then it would be providing that to the object you are modeling, which means you’ll want to look into how your framework populates select box values.