curl --request POST \
  --url https://dev-api-cj-agc-vie.fnstack.dev/v1/charges/airtel/c2b/transaction-enquiry \
  --header 'Content-Type: application/xml' \
  --header 'x-api-key: <api-key>' \
  --data '
{
  "COMMAND": {
    "TXNID": "<string>",
    "MSISDN": "<string>"
  }
}
'

{
  "COMMAND": {
    "REF": "<string>",
    "STATUS": 123,
    "MESSAGE": "<string>"
  }
}