CORS policy don’t want to work with SignalR and ASP.NET core

I solved my problem according to this link

Add this block code to service

services.AddCors(options => options.AddPolicy("CorsPolicy",
        builder =>
        {
            builder.AllowAnyHeader()
                   .AllowAnyMethod()
                   .SetIsOriginAllowed((host) => true)
                   .AllowCredentials();
        }));

and add this block code in configuring app

app.UseCors("CorsPolicy");
app.UseSignalR(routes =>
        {
            routes.MapHub<General>("/hubs/general");
        });