A snippet for using Watson Assistant with API key authentication

WatsonAssistantApiKey.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using IBM.Watson.DeveloperCloud.Services.Assistant.v1;
using IBM.Watson.DeveloperCloud.Utilities;
using IBM.Watson.DeveloperCloud.Logging;
using IBM.Watson.DeveloperCloud.Connection;
using FullSerializer;
using IBM.Watson.DeveloperCloud.DataTypes;

public class WatsonAssistantApiKey : MonoBehaviour
{
#region PLEASE SET THESE VARIABLES IN THE INSPECTOR
    [Header("Watson Assistant")]
    [Tooltip("The service URL (optional). This defaults to \"https://gateway.watsonplatform.net/assistant/api\"")]
    [SerializeField]
    private string assistantURL;
    [SerializeField]
    private string assistantWorkspace;
    [Header("CF Authentication")]
    [SerializeField]
    private string assistantUsername;
    [SerializeField]
    private string assistantPassword;
    [Header("IAM Authentication")]
    [Tooltip("The IAM apikey.")]
    [SerializeField]
    private string assistantIamApikey;
    [Tooltip("The IAM url used to authenticate the apikey (optional). This defaults to \"https://iam.bluemix.net/identity/token\".")]
    [SerializeField]
    private string assistantIamUrl;

#endregion

private void Start(){

  Credentials asst_credentials = null;
        if(!string.IsNullOrEmpty(assistantUsername) && !string.IsNullOrEmpty(assistantPassword)){
            
            //Authenticate using username and password
            asst_credentials = new Credentials(assistantUsername, assistantPassword, assistantURL);
            _assistant = new Assistant(asst_credentials);
            //be sure to give it a Version Date
            _assistant.VersionDate = "2018-09-20";
        } else if(!string.IsNullOrEmpty(assistantIamApikey)) {
            
            //Authenticate using iamApikey
            TokenOptions tokenOptions = new TokenOptions()
            {
                IamApiKey = assistantIamApikey,
                IamUrl = assistantIamUrl
            };

            asst_credentials = new Credentials(tokenOptions, assistantURL);
        } else {
            throw new WatsonException("Please provide either username and password or IAM apikey to authenticate the service.");
        }
   }
        
}