Unable to get Embed Token (Access Token and Embed URL done)

[Anonymous]

Hi, I've tried many ways (Powershell, Azure Function, etc.) to get the Embed Token. But none of that works, I always received Forbidden (403). Below is my code in Azure, Function. I obtained AccessToken successfully, which means I am authorized. I received the Embed URL too. However, the step always fails at generate Embed Token's step.

#r "System.Web.Extensions"  
using System.Configuration;  
using System.Net;  
using System.Text;  
using System.Web.Script.Serialization;  
using Microsoft.IdentityModel.Clients.ActiveDirectory;  
using Microsoft.PowerBI.Api.V2;  
using Microsoft.PowerBI.Api.V2.Models;  
using Microsoft.Rest;  
  
// Static Values  
static string authorityUrl = "https://login.windows.net/common/oauth2/authorize/";  
static string resourceUrl = "https://analysis.windows.net/powerbi/api";  
static string apiUrl = "https://api.powerbi.com/";  
static string clientId = ConfigurationManager.AppSettings["PBIE_CLIENT_ID"];  
static string username = ConfigurationManager.AppSettings["PBIE_USERNAME"];  
static string password = ConfigurationManager.AppSettings["PBIE_PASSWORD"];  
static string groupId = ConfigurationManager.AppSettings["PBIE_GROUP_ID"];  
static string reportId = ConfigurationManager.AppSettings["PBIE_REPORT_ID"];  
  
public static async Task<HttpResponseMessage> Run(HttpRequestMessage req, TraceWriter log)  
{  
  
    // Authenticate with Azure Ad > Get Access Token > Get Token Credentials  
    var credential = new UserPasswordCredential(username, password);  
    string myCredential = credential.ToString();
    var authenticationContext = new AuthenticationContext(authorityUrl);  
    var authenticationResult = await authenticationContext.AcquireTokenAsync(resourceUrl, clientId, credential);  
    string accessToken = authenticationResult.AccessToken;
    log.Info(accessToken); 
    var tokenCredentials = new TokenCredentials(accessToken, "Bearer");  
      
    using (var client = new PowerBIClient(new Uri(apiUrl), tokenCredentials))  
    {  
        // Embed URL  
        Report report = client.Reports.GetReportInGroup(groupId, reportId);  
        string embedUrl = report.EmbedUrl;  
        log.Info(embedUrl);
  
        // Embed Token (Step that fails!!) 
        var generateTokenRequestParameters = new GenerateTokenRequest(accessLevel: "view"); 
        EmbedToken embedToken = client.Reports.GenerateTokenInGroup(groupId, reportId, generateTokenRequestParameters);  
        

        // JSON Response  
        EmbedContent data = new EmbedContent();  
        data.EmbedToken = embedToken.Token;  
        data.EmbedUrl = embedUrl;  
        data.ReportId = reportId;  
        JavaScriptSerializer js = new JavaScriptSerializer();  
        string jsonp = "callback(" +  js.Serialize(data) + ");";  
  
        // Return Response  
        return new HttpResponseMessage(HttpStatusCode.OK)   
        {  
            Content = new StringContent(jsonp, Encoding.UTF8, "application/json")  
        };  
    }  
}  
  
public class EmbedContent  
{  
    public string EmbedToken { get; set; }  
    public string EmbedUrl { get; set; }  
    public string ReportId { get; set; }  
}  

Output: 

2019-03-27T03:23:55.435 [Error] Exception while executing function: Functions.getEmbedToken. Microsoft.Azure.WebJobs.Script: One or more errors occurred. Microsoft.PowerBI.Api: Operation returned an invalid status code 'Forbidden'.

2019-03-27T03:23:55.482 [Error] Function completed (Failure, Id=5c8fa500-7bd9-49a5-97e6-975d25eb02fd, Duration=1061ms)

I've spent a lot of time researching for this problem. Hope someone could help me on this. Appreciate much. Thanks in advance.