Create a message

curl --request POST \
  --url https://app.chatwoot.com/public/api/v1/inboxes/{inbox_identifier}/contacts/{contact_identifier}/conversations/{conversation_id}/messages \
  --header 'Content-Type: application/json' \
  --data '{
  "content": "Hello, how can I help you?",
  "echo_id": "1234567890"
}'

{
  "id": "<string>",
  "content": "<string>",
  "message_type": "<string>",
  "content_type": "<string>",
  "content_attributes": "<string>",
  "created_at": "<string>",
  "conversation_id": "<string>",
  "attachments": [
    {}
  ],
  "sender": {}
}