I was able to load the new API reference using the below method.

using Acumatica.Default_22_200_001.Model;
using Acumatica.RESTClient.Client;

using static Acumatica.RESTClient.AuthApi.AuthApiExtensions;
using static Acumatica.RESTClient.ContractBasedApi.ApiClientExtensions;  

var client = new ApiClient(siteURL);
client.Login(username, password, tenant, branch, locale);