curl --request POST \
  --url https://www.chatbase.co/api/v1/chatbots/{chatbotId}/contacts \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "users": [
    {
      "external_id": "user_123",
      "name": "John Doe",
      "email": "john@example.com",
      "phonenumber": "+1234567890",
      "stripe_accounts": [
        {
          "label": "main",
          "stripe_id": "cus_123abc456",
          "stripe_email": "john@example.com"
        }
      ],
      "custom_attributes": {
        "department": "Sales",
        "subscription_tier": "Premium"
      }
    }
  ]
}
'

{
  "message": "Success",
  "data": [
    {
      "id": "contact_internal_123",
      "external_id": "user_123",
      "name": "John Doe",
      "email": "john@example.com",
      "phonenumber": "+1234567890",
      "stripe_accounts": [
        {
          "label": "main",
          "stripe_id": "cus_123abc456",
          "stripe_email": "john@example.com"
        }
      ],
      "custom_attributes": {
        "department": "Sales",
        "subscription_tier": "Premium"
      },
      "created_at": 1704067200,
      "updated_at": 1704153600
    }
  ]
}