How can I use AdvancedPlatformDelivery to send push notifications?

I don't understand how to use AdvancedPlatformDelivery-Version to send push notifications to a registered iOS/Android device. I want to send a message with the Title: "Welcome message" and the message body "Hello "+ displayname of the Player. How can I do that?

Can I use one cloud script version for Android and iOS or is it necessary to create two different cloud scripts(one for iOS and one for Android)?

My cloud script:

handlers.Welcome = function (args, context)
{
    try
    {
    jsonObjectIOS =
    {
	"customData" : customDataString, // include any additional data here
	"content-available": 1
    };
 
    let jsonStringIOS = JSON.stringify(jsonObjectIOS);
 
    let plattformIOS = "ApplePushNotificationService";
 
    let pushNotificationResult = server.SendPushNotification
    ({
	    Recipient: recipientPlayFabId,
        AdvancedPlatformDelivery:
        [
            {
                Json: jsonStringAndroid,
                Platform: plattformAndroid
            },
            {
        	    Json: jsonString,
                Platform: plattformIOS
            }
        ]
    });
        server.SendPushNotification({ Package : { Message : "Hello", Title: "Welcome message" }});
   }
   catch (ex)
   {
        // Target player has not registered for Push Notifications
   }
}

client application code:

string Errormsg = "";

private async Task SendPushNotification()
{
  var result = await PlayFabClientAPI.ExecuteCloudScriptAsync(new ExecuteCloudScriptRequest()
  {
    FunctionName = "Welcome",
    GeneratePlayStreamEvent = true
  });

  if (result.Error != null)
    Errormsg = result.Error.Error.ToString();
  else
    Errormsg = "Sending Push notification successful?";
}