curl --request POST \
  --url https://sandbox-biller-b2b.singapay.id/api/v1/check-balance \
  --header 'Accept: <accept>' \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --header 'X-PARTNER-ID: <x-partner-id>' \
  --data '
{
  "command": "check-balance"
}
'

{
  "command": "check-balance",
  "response_code": "00",
  "response_text": "Operation completed successfully",
  "data": {
    "balance": "8910003.00",
    "currency": "IDR"
  }
}