JSON Adding values to a class

Kind of new (inexperienced) to JSON. I’m trying to add an accessorial code in my project. Example codes is "HAZ".

I’ve created a public class for Accessorials (see below) and in that class I have "Public codes As String()".

Public Class Accessorials
    Public codes As String()
    Public hazardousContact As HazardousContact
    Public cod As Object
    Public insuranceDetails As Object
    Public sortAndSegregateDetails As Object
    Public markDetails As Object
End Class

Which in turn feeds the primary Wrapper

Public Class fgtload 'Primary wrapper
    Public service As New fgtservice
    Public payment As New fgtpayment
    Public transit As New fgttransit
    Public commodities As New List(Of Items)
    Public origin As New fgtorigin
    Public destination As New fgtdestination
    Public billTo As New fgtbillto
    **Public accessorials As New Accessorials**
End Class

I’m trying to add the code "HAZ" to the class Accessorials.
which shows the code as " Public codes As String()"
I’m assuming by the () that it’s looking for an array of sorts.
Should (within the primary wrapper) accessorials be a List(Of Accessorials) ?

The outcome should be :

"accessorials" : {
    "codes" : [ "HAZ" ],
    "hazardousContact" : {
    "name" : "John Snow",
    "phone" : "7704865900"
},

Here’s the full JSON from the API Guide

{"service":{"level":"STND"},"payment":{"terms":"Prepaid","payer":"Shipper"},"transit":{"pickupDate":"20230930"},"commodities":[{"classification":"92.5","weight":"1500","length":"48","width":"40","height":"40","pieces":"3","packagingType":"PAT","description":"Umbrellas","stackable":"Y"},{"classification":"50","weight":"50","length":"48","width":"48","height":"48","pieces":"5","packagingType":"PAT","description":"Soda","stackable":"N"}],"accessorials":{"codes":["HAZ"],"hazardousContact":{"name":"John Snow","phone":"7704865900"},"cod":null,"insuranceDetails":null,"sortAndSegregateDetails":null,"markDetails":null},"origin":{"account":"1234567","city":"LEBANON","stateProvince":"TN","postalCode":"37090","country":"USA"},"destination":{"account":"","city":"Calgary","stateProvince":"AB","postalCode":"T1Y2S2","country":"CAN"},"billTo":{"account":"","name":"Bill To Company","address":"456 Bill Me Rd.","city":"LEBANON","stateProvince":"TN","postalCode":"37090","country":"USA"}}