curl --request GET \
  --url https://tonapi.io/v2/gasless/config

{
  "relay_address": "0:dfbd5be8497fdc0c9fcbdfc676864840ddf8ad6423d6d5657d9b0e8270d6c8ac",
  "gas_jettons": [
    {
      "master_id": "<string>"
    }
  ]
}

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