Vmss instance count using C#

I want to auto scale up / down the Azure virtual machine scale set by updating the instance value using C#. Please suggest how it can be done using C#.

using Microsoft.Azure.Management.Fluent;
using Microsoft.Azure.Management.ResourceManager.Fluent;
using System;

namespace vmssScale
{
    class Program
    {
        static void Main(string[] args)
        {
            var AppId = "2822a0d2-04f4-4337-aa0b-481963d5f37f";
            var AppSecret = "K3b7rzZQ9-fOCj.Pv~ctRm5_ZgVkoK.355";
            var tenant = "afebbe05-f314-492a-9035-3b68dee7fea1";
            var subscriptionID = "f1b96a0f-2775-420f-b692-3f13bcdf0060";
            var vmScaleSetGroup = "devtest-RG";
            var vmScaleSetName = "devVMSS";

            var credentials = SdkContext.AzureCredentialsFactory.FromServicePrincipal(AppId, AppSecret, tenant, AzureEnvironment.AzureGlobalCloud);
            var azure = Azure.Configure().Authenticate(credentials).WithSubscription(subscriptionID);

            var vmScaleSetID = "/subscriptions/" + subscriptionID + "/resourceGroups/" + vmScaleSetGroup + "/providers/Microsoft.Compute/virtualMachines/" + vmScaleSetName;


            var vmScaleSet = azure.VirtualMachineScaleSets.GetById(vmScaleSetID);
            //set as 5 instance
            var instanceValue = 3;

            Console.WriteLine("start to change instance value,it will take several mins...");
            vmScaleSet.Update().WithCapacity(instanceValue).Apply();

            Console.WriteLine("Done");
        }
    }
}