How to use appsettings.json in Asp.net core 6 Program.cs file

While the examples above work, the way to do this is the following:

var builder = WebApplication.CreateBuilder(args);
// Add services to the container.
builder.Services.AddControllers();
builder.Services.AddStackExchangeRedisCache(options =>
{
    options.Configuration = builder.Configuration["Redis"];
});

The WebApplicationBuilder has a configuration object as a property that you can use.