getblockhash

// Request
curl -H "Content-Type: application/json" -d '{"id":1, "jsonrpc":"2.0", "method": "getblockhash","params": [1000]}' http://<your-app-id>.ankr.com
​
// Result
{
  "jsonrpc": "2.0",
  "id": 1,
  "result": "0x77ce0a3695891e7a623fb0c28d6670d66fec5061c5c333df3570fffd42e4af19"
}