Dialogflow CX Webhook Response format

[SandeepPinniti]

Hi,

I have linked the routes with a webhook, so when an intent is detected the webhook is triggered and the webhook sends the response back to the dialogflow. I'm getting different types of messages on the Intent object as shown below, will you please help me understand how the webhook response should look like. I'm using Google Dialogflow C# client libraries to serialize the webhook response and pass it back. 

Use case 1: "Unauthorized FulfillmentResponse": false

Use case 2: "ErrorCode": "INVALID_ARGUMENT", "ErrorMessage": "Error calling webhook Failed to parse webhook response"

I'm trying to pass back the below response

{
"FulfillmentResponse": {
"Messages": [
{
"Text": {
"Text_": [
"Hi"
],
"AllowPlaybackInterruption": false
},
"Payload": null,
"ConversationSuccess": null,
"OutputAudioText": null,
"LiveAgentHandoff": null,
"EndInteraction": null,
"PlayAudio": null,
"MixedAudio": null,
"TelephonyTransferCall": null,
"ResponseType": 0,
"Channel": "",
"MessageCase": 1
}
],
"MergeBehavior": 0
},
"PageInfo": null,
"SessionInfo": null,
"Payload": null,
"TargetPage": "",
"HasTargetPage": false,
"TargetFlow": "",
"HasTargetFlow": false,
"TransitionCase": 0,
"TargetPageAsPageName": null,
"TargetFlowAsFlowName": null
}

Thanks in advance.