curl http://127.0.0.1:18081/json_rpc -d '{"jsonrpc":"2.0","id":"0","method":"get_block_header_by_height","params":{"height":912345}}' -H 'Content-Type: application/json'
{
  "error": {
    "code": -32700,
    "message": "Parse error"
  },
  "id": 0,
  "jsonrpc": "2.0"
}curl: (6) Could not resolve host: application