curl --request GET \
  --url https://trade.predexon.com/api/accounts/{accountId}/balance \
  --header 'x-api-key: <api-key>'

{
  "balances": [
    {
      "venue": "<string>",
      "available": "<string>",
      "locked": "<string>",
      "total": "<string>"
    }
  ],
  "_meta": {
    "venues": [
      {
        "venue": "<string>",
        "status": "ok"
      }
    ]
  }
}