have a problem with Power BI Embedded. I want to embed a power BI report in a partial view. Following the guide, I created these methods on my controller:
public ActionResult Report()
    {
        credential = new UserCredential(username, passwordPowerBI);
        Authorize().Wait();
        ReportEmbed myReport = new ReportEmbed();
        using (var client = new PowerBIClient(new Uri(apiUrl), tokenCredentials))
        {
            EmbedToken embedToken = client.Reports.GenerateTokenInGroup(groupId, reportID, new GenerateTokenRequest(accessLevel: "View"));
            Report report = client.Reports.GetReportInGroup(groupId, reportID);
            myReport.reportID = reportID;
            myReport.embedURL = report.EmbedUrl;
            myReport.embedToken = embedToken.Token;
        }
        return PartialView(myReport);
    }
    private static Task Authorize()
    {
        return Task.Run(async () => {
            authenticationResult = null;
            tokenCredentials = null;
            var authenticationContext = new AuthenticationContext(authorityUrl);
            authenticationResult = await authenticationContext.AcquireTokenAsync(resourceUrl, clientID, credential);
            if (authenticationResult != null)
            {
                tokenCredentials = new TokenCredentials(authenticationResult.AccessToken, "Bearer");
            }
        });
    }
And in the view I just try to view my report. But the application go to this exception:

(sorry, some text is in italian. "Impossibile trovare il metodo" means "Method not found").
What is the problem? Something is missing in the web.config?