Startup.cs

[assembly: FunctionsStartup(typeof(Startup))]
namespace MyFunctionsProject
{
  public class Startup : FunctionsStartup
  {
    public override void Configure(IFunctionsHostBuilder builder)
    {
      // this will bind to the "Values" section of the configuration
      builder
          .Services
          .AddOptions<ApplicationSettings>()
          .Configure<IConfiguration>((settings, configuration) => { configuration.Bind(settings); });

      // this will bind to a specific section of the configuration
      // by using the section name, in this case "ConnectionStrings"
      builder
          .Services
          .AddOptions<ConnectionStrings>()
          .Configure<IConfiguration>((settings, configuration) => { configuration.Bind("ConnectionStrings", settings); });
    }
  }
}