Flow Template

Payload

{
    "messages": [
        {
            "sender": "91xxxxxxxxxx",
            "to": "91xxxxxxxxxx",
            "messageId": "1234",
            "transactionId": "trn12",
            "channel": "wa",
            "type": "template",
            "template": {
                "body": [],
                "templateId": "ankit_extensions_1",
                "langCode": "en",
                "buttons": [
                    {
                        "index": "0",
                        "subType": "flow",
                        "parameters": {
                            "type": "action",
                            "flow_token": "123455"
                        }
                    }
                ]
            }
        }
    ],
    "responseType": "json"
}

Note: 'type' field will have the value as 'template', 'subType' field will have the value as 'flow', 'templateID' field refers to template name which should be passed in small characters only, 'button' object will have 'index' field which can have values between 0-2 depending on the number of Quick Reply buttons.