curl --request POST \
  --url 'https://rpc-mainnet.solanatracker.io/?api_key=' \
  --header 'Content-Type: application/json' \
  --data '
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "getBalance",
  "params": [
    "83astBRguLMdt2h5U1Tpdq5tjFoJ6noeGwaY3mDLVcri"
  ]
}
'

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "context": {
      "slot": 372910193
    },
    "value": 0
  }
}