private async Task getInvoiceDetailsAsync(IDialogContext context, IAwaitable<object> result)
    {
        var activity = await result as Activity;
        companyName = activity.Text;
        noOfCompany = 10;

        // calling the Api to get invoice details
        InvoiceDetailsController obj = new InvoiceDetailsController();

        // store return data in to a list
        returnInvoiceDetails = obj.getInvoiceDetails(userid, companyName, noOfCompany);
        invoiceCount = obj.getItems();

        // checking if the return list contains any useful values

        if (invoiceCount!=0) {
            for (int i = 0; i < invoiceCount; i++)
            {
                customerID[i] = returnInvoiceDetails[i].customer_id.ToString();
                settleamount[i] = float.Parse(returnInvoiceDetails[i].settle_amount.ToString());
                settAmount[i] = settleamount[i].ToString("#,##0");
            }
            var selectedCard = await result;
            var message = context.MakeMessage();
            // calling the card to show details

            var attachment = invoiceCard();
            message.Attachments.Add(attachment);
            await context.PostAsync(message); }
            context.Wait(MessageReceivedAsync);

    }


    private static Attachment invoiceCard()
    {
        ThumbnailCard invoiceDetails = new ThumbnailCard
        {
            Images = new List<CardImage> {
             new CardImage("https://thumb9.shutterstock.com/display_pic_with_logo/701173/108824516/stock-photo-cloud-computing-concept-isolated-on-white-background-d-rendered-108824516.jpg"), },
            Title = "<b><u><font color ="#721B59">These are the Invoice Details for " + companyName+ "<b><u><font color ="#721B59"></font></b></u>",
            Text = $"<b>Customer Id :-</b>" + "            " + customerID[0] + "<br> <b>Settlement amount :-</b>" + "            " + settAmount[0] +
                       "<br><br><b>Customer Id :-</b>" + "            " + customerID[1] + "<br> <b>Settlement amount :-</b>" + "            " + settAmount[1] +
                       "<br><br><b>Customer Id :-</b>" + "            " + customerID[2] + "<br> <b>Settlement amount :-</b>" + "            " + settAmount[2] +
                       "<br><br><b>Customer Id :-</b>" + "            " + customerID[3] + "<br> <b>Settlement amount :-</b>" + "            " + settAmount[3] +
                       "<br><br><b>Customer Id :-</b>" + "            " + customerID[4] + "<br> <b>Settlement amount :-</b>" + "            " + settAmount[4],
            Buttons = new List<CardAction>
                        {
                            new CardAction(ActionTypes.ImBack,"Thank you",value:"U0001F642")
                        },
        };

        return invoiceDetails.ToAttachment();
    }

<?xml version="1.0" encoding="utf-8"?>
<!--
  For more information on how to configure your ASP.NET application, please visit
  http://go.microsoft.com/fwlink/?LinkId=301879
  -->
<configuration>
  <appSettings>
    <!-- update these with your BotId, Microsoft App Id and your Microsoft App Password-->
    <add key="BotId" value="AX_Bot" />

    <add key="MicrosoftAppId" value="" />
    <add key="MicrosoftAppPassword" value="" />

  </appSettings>
  <!--
    For a description of web.config changes see http://go.microsoft.com/fwlink/?LinkId=235367.

    The following attributes can be set on the <httpRuntime> tag.
      <system.Web>
        <httpRuntime targetFramework="4.6" />
      </system.Web>
  -->
  <system.web>
    <customErrors mode="Off" />
    <compilation debug="true" targetFramework="4.6" />
    <httpRuntime targetFramework="4.6" />
  </system.web>
  <system.webServer>
    <defaultDocument>
      <files>
        <clear />
        <add value="default.htm" />
      </files>
    </defaultDocument>

  <handlers>
      <remove name="ExtensionlessUrlHandler-Integrated-4.0" />
      <remove name="OPTIONSVerbHandler" />
      <remove name="TRACEVerbHandler" />
      <add name="ExtensionlessUrlHandler-Integrated-4.0" path="*." verb="*" type="System.Web.Handlers.TransferRequestHandler" preCondition="integratedMode,runtimeVersionv4.0" />
    </handlers></system.webServer>
  <runtime>
    <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
      <dependentAssembly>
        <assemblyIdentity name="System.Web.Helpers" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Web.Mvc" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="1.0.0.0-5.2.3.0" newVersion="5.2.3.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Web.WebPages" publicKeyToken="31bf3856ad364e35" />
        <bindingRedirect oldVersion="1.0.0.0-3.0.0.0" newVersion="3.0.0.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="Newtonsoft.Json" publicKeyToken="30ad4fe6b2a6aeed" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-8.0.0.0" newVersion="8.0.0.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Net.Http.Primitives" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-4.2.29.0" newVersion="4.2.29.0" />
      </dependentAssembly>
      <dependentAssembly>
        <assemblyIdentity name="System.Net.Http.Formatting" publicKeyToken="31bf3856ad364e35" culture="neutral" />
        <bindingRedirect oldVersion="0.0.0.0-5.2.3.0" newVersion="5.2.3.0" />
      </dependentAssembly>

    </assemblyBinding>
  </runtime>
</configuration>