curl --request POST \
  --url https://perp-api.phoenix.trade/v1/ix/place-isolated-market-order-enhanced \
  --header 'Content-Type: application/json' \
  --data '
{
  "authority": "string",
  "side": "string",
  "symbol": "string"
}
'

{
  "instructions": [
    {
      "data": [
        1
      ],
      "keys": [
        {
          "isSigner": true,
          "isWritable": true,
          "pubkey": "<string>"
        }
      ],
      "programId": "<string>"
    }
  ],
  "estimatedLiquidationPriceUsd": 123
}