Program.cs

using threads_app;

var  MyAllowSpecificOrigins = "_myAllowSpecificOrigins";

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddCors(options =>
{
    options.AddPolicy(name: MyAllowSpecificOrigins,
                      policy  =>
                      {
                          policy.WithOrigins("http://127.0.0.1:8080");
                      });
});

// Add services to the container. 
// Learn more about configuring Swagger/OpenAPI at https://aka.ms/aspnetcore/swashbuckle
builder.Services.AddControllers();
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();

DependencyManager.AddDependencies(builder);

var app = builder.Build();

// Configure the HTTP request pipeline.
if (app.Environment.IsDevelopment()) 
{
    app.UseSwagger();
    app.UseSwaggerUI();
}

app.UseHttpsRedirection();

app.UseStaticFiles();
app.MapFallbackToFile("index.html");

app.UseCors(MyAllowSpecificOrigins);

app.MapControllers();

app.Run();