Startup.cs

public class Startup
{
    ...
    public void ConfigureServices(IServiceCollection services)
    {
        ...

        services.AddControllers().AddJsonOptions(Constants.JsonOptionsNames.DeliveryApi, options =>
        {
            // To resolve System.Text.Json polymorphic type resolving issue for the query controller
            options.JsonSerializerOptions.TypeInfoResolver = new FallbackDeliveryApiJsonTypeResolver();
        });
        
        // Overwrite the default ApiContentResponseBuilder to add "system" section
        services.AddSingleton<IApiContentResponseBuilder, ExtendedApiContentResponseBuilder>();
    }
}