curl --request POST \
  --url 'https://api.avax.network/ext/bc/P#platform.getRewardUTXOs' \
  --header 'Content-Type: application/json' \
  --data '
{
  "jsonrpc": "2.0",
  "method": "platform.getRewardUTXOs",
  "params": {},
  "id": 1
}
'

{
  "jsonrpc": "2.0",
  "result": {
    "numFetched": "1000000000",
    "utxos": [
      "<string>"
    ],
    "encoding": "hex"
  },
  "id": 1
}