SignalR authorization, Angular, ASP.NET Core

Question

Hello,

In my app I use IdentityServer4 for my web API. Now I want to use SignalR but I always get error 401. With my other http.get <T> calls I have no problems.

[Authorize(AuthenticationSchemes = IdentityServerAuthenticationDefaults.AuthenticationScheme)]
public class ChatHub : Hub

In the Angular Service I initialize the hub as follows.

const tokenValue = '?token=' + this.authService.accessToken;
const hubUrl = `${this.configurations.baseUrl + '/hubs/chat?'}looney${tokenValue}`;

this.hubConnection = new signalR.HubConnectionBuilder().withUrl(hubUrl).configureLogging(signalR.LogLevel.Information).build();

 For the other http.get I set the request headers as follows:

protected get requestHeaders(): { headers: HttpHeaders | { [header: string]: string | string[]; } } {
    const headers = new HttpHeaders({
      Authorization: 'Bearer ' + this.authService.accessToken,
      'Content-Type': 'application/json',
      Accept: 'application/json, text/plain, */*'
    });

    return { headers };
}

Can someone help me here??

Thanks in advance for any advice or tip