var images = new List <CardImage> ();
HeroCard _card = new HeroCard();
string apiKey = "<your_generated_api_key>";
string storeAddress = "Banaras";
images.Add(
new CardImage($"https://maps.googleapis.com/maps/api/staticmap?zoom=17&scale=2&size=600x300&maptype=roadmap&key={apiKey}&format=png&visual_refresh=true&markers=size:mid%10Ccolor:0xff0000%7Clabel:1%7C" + storeAddress));
var buttons = new List < CardAction > ();
buttons.Add(new CardAction(ActionTypes.OpenUrl, "Directions", value: $ "https://www.google.co.in/maps/dir/{"
"}/{storeAddress}"));
_card.Buttons = buttons;
_card.Images = images;
await turnContext.SendActivityAsync(MessageFactory.Attachment(_card.ToAttachment()), cancellationToken);