Embed for customers- Fail to initialize - Could not resolve cluster

As per https://docs.microsoft.com/en-us/power-bi/developer/embedded-troubleshoot. 

My code is pretty similar and it works:

public async Task<AzureToken> GetAzureTokenDataAsync()
		{
			string authorityUrl = $"{_azureSettings.Instance}{_azureSettings.TenantId}/oauth2/token";

			Uri oauthEndpoint = new Uri(authorityUrl);

			using (HttpClient httpClient = new HttpClient())
			{
				HttpResponseMessage responseMessage = await httpClient.PostAsync(oauthEndpoint, new FormUrlEncodedContent(new[]
				{
					 new KeyValuePair<string, string>("resource", _powerBiSettings.ResourceUrl),
					 new KeyValuePair<string, string>("client_id", _azureSettings.ClientId),
					 new KeyValuePair<string, string>("grant_type", "password"),
					 new KeyValuePair<string, string>("username", _powerBiSettings.Username),
					 new KeyValuePair<string, string>("password", _powerBiSettings.Password),
					 new KeyValuePair<string, string>("scope", "openid"),
				 }));

				string responseText = await responseMessage.Content.ReadAsStringAsync();

				OAuthResult authenticationResult = JsonConvert.DeserializeObject<OAuthResult>(responseText);

				TokenCredentials tokenCredentials = new TokenCredentials(authenticationResult.AccessToken, "Bearer");

				return new AzureToken(tokenCredentials, authenticationResult.AccessToken);
			}
		}

		private class OAuthResult
		{
			[JsonProperty("token_type")]
			public string TokenType { get; set; }

			[JsonProperty("scope")]
			public string Scope { get; set; }

			[JsonProperty("expires_in")]
			public int ExpiresIn { get; set; }

			[JsonProperty("ext_expires_in")]
			public int ExtExpiresIn { get; set; }

			[JsonProperty("expires_on")]
			public int ExpiresOn { get; set; }

			[JsonProperty("not_before")]
			public int NotBefore { get; set; }

			[JsonProperty("resource")]
			public Uri Resource { get; set; }

			[JsonProperty("access_token")]
			public string AccessToken { get; set; }

			[JsonProperty("refresh_token")]
			public string RefreshToken { get; set; }
		}

public async Task<EmbeddedReportConfig> GetReportForIdAsync(Guid reportId, string name, string roles)
		{
			var result = new EmbeddedReportConfig();

			try
			{
				AzureToken azureToken = await _authenticationHandler.GetAzureTokenDataAsync();

				using (PowerBIClient powerBiClient = new PowerBIClient(new Uri(_powerBiSettings.ApiUrl), azureToken.TokenCredentials))
				{
					Report powerBiReport = await powerBiClient.Reports.GetReportAsync(_powerBiSettings.WorkspaceId, reportId.ToString());

					List<EffectiveIdentity> rowLevelSecurityIdentity = new List<EffectiveIdentity>
					{
						new EffectiveIdentity(
							name,
							//roles: new List<string> { role },
							datasets: new List<string> {powerBiReport.DatasetId}
						)
					};

					GenerateTokenRequest powerBiTokenRequestParameters = new GenerateTokenRequest("View", powerBiReport.DatasetId, false, rowLevelSecurityIdentity);

					EmbedToken powerBiTokenResponse = await powerBiClient.Reports.GenerateTokenInGroupAsync(_powerBiSettings.WorkspaceId, powerBiReport.Id, powerBiTokenRequestParameters);

					return new EmbeddedReportConfig
					{
						Id = powerBiReport.Id,
						Name = powerBiReport.Name,
						EmbedUrl = powerBiReport.EmbedUrl,
						AccessToken = powerBiTokenResponse.Token
					};
				}
			}
			catch (HttpOperationException ex)
			{
				// https://community.powerbi.com/t5/Developer/quot-shouldn-t-have-effective-identity-quot-error-when-passing/td-p/433730
				// https://docs.microsoft.com/en-us/power-bi/developer/embedded-row-level-security
				//Bad Request
				var content = ex.Response.Content;
				Console.WriteLine(content);

				return null;
			}
		}

There is also this https://stackoverflow.com/a/52998483/5209435. I hope this helps.