Fetch the number of owners of all MTs issued by the MT contract.
curl -i -X GET \ -u <username>:<password> \ 'https://th-api.klaytnapi.com/v2/contract/mt/{mt-address}/holder' \ -H 'x-chain-id: string'
{- "address": "0x251f622e8b5e713f357e9c4d990e91da2f448134",
- "totalHolder": 48
}