curl --request POST \
  --url 'https://partner.gupshup.io/partner/bizgate/app/6f414190-d45c-4671-bca1-fb6c3018cb13/messaging' \
  --header 'Authorization: Bearer <UT>' \
  --header 'Content-Type: application/json' \
  --data '{
  "messaging_product": "whatsapp",
  "recipient_type": "individual",
  "to": "91XXXXXXXX10",
  "type": "interactive",
  "interactive": {
    "type": "flow",
    "header": {
      "type": "text",
      "text": "Book your appointment"
    },
    "body": {
      "text": "Pick a slot that works for you."
    },
    "footer": {
      "text": "Takes under a minute"
    },
    "action": {
      "name": "flow",
      "parameters": {
        "flow_message_version": "3",
        "flow_token": "flow-token-10482",
        "flow_id": "1873455556789012",
        "flow_cta": "Book now",
        "flow_action": "navigate",
        "flow_action_payload": {
          "screen": "APPOINTMENT",
          "data": {
            "product_name": "Gardening workshop",
            "product_description": "90-minute hands-on session",
            "product_price": 1299
          }
        }
      }
    }
  }
}
'

{
  "messages": [
    {
      "id": "GUPSHUP_MESSAGE_ID"
    }
  ],
  "messaging_product": "whatsapp",
  "contacts": [
    {
      "input": "DESTINATION_PHONE_NO",
      "wa_id": "DESTINATION_PHONE_NO"
    }
  ]
}