curl --request GET \
  --url https://tonapi.io/v2/rates/markets

{
  "markets": [
    {
      "market": "OKX",
      "usd_price": 5.2,
      "last_date_update": 1668436763
    }
  ]
}

{
  "error": "<string>",
  "error_code": 123
}