curl --request POST \
  --url https://api.kupe.in/api/v1/batch-call/{batch_id}/data/upsert \
  --header 'Content-Type: application/json' \
  --header 'x-api-key: <api-key>' \
  --data '
{
  "items": [
    {
      "to_phonenumber": "<string>",
      "id": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
      "variable_values": {}
    }
  ]
}
'

{}