btcpayserver/BTCPayServer/Extensions/ServiceCollectionExtensions.cs

using BTCPayServer.Hosting;

namespace Microsoft.Extensions.DependencyInjection
{
    public static class ServiceCollectionExtensions
    {
        public static IServiceCollection AddStartupTask<T>(this IServiceCollection services)
            where T : class, IStartupTask
            => services.AddTransient<IStartupTask, T>();
    }
}