curl --request POST \
  --url https://perp-api.phoenix.trade/v1/exchange/build-register-ixs \
  --header 'Content-Type: application/json' \
  --data '
{
  "traderAuthority": "string",
  "txFeePayer": "string"
}
'

{
  "includeRegisterTrader": true,
  "instructions": [
    {
      "data": [
        1
      ],
      "keys": [
        {
          "isSigner": true,
          "isWritable": true,
          "pubkey": "<string>"
        }
      ],
      "programId": "<string>"
    }
  ],
  "maxPositions": 1,
  "traderOnboarder": "<string>",
  "traderPda": "<string>",
  "txFeePayer": "<string>"
}