Program.cs

using HealthChecks.UI.Client;
using Microsoft.AspNetCore.Diagnostics.HealthChecks;

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.
builder.Services.AddRazorPages();


builder.Services.AddHealthChecks()
    .AddUrlGroup(sp =>
    {
        var uris = new string[]{ "http://www.google.es", "https://www.bing.es" };
        var selected  = Random.Shared.NextInt64() % 2 == 0 ? uris[0] : uris[1];

        return new Uri(selected);
    });

var app = builder.Build();

// Configure the HTTP request pipeline.
if (!app.Environment.IsDevelopment())
{
    app.UseExceptionHandler("/Error");
    // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
    app.UseHsts();
}

app.UseHttpsRedirection();
app.UseStaticFiles();

app.UseRouting();

app.UseAuthorization();

app.MapRazorPages();

app.MapHealthChecks("/ready", new HealthCheckOptions()
{
    Predicate = _ => true,
    AllowCachingResponses = false,
    ResponseWriter = UIResponseWriter.WriteHealthCheckUIResponse
});

app.Run();