curl https://mainnet.arbitrum.validationcloud.io/v1/<YOUR_API_KEY_HERE> \
-X POST \
-H "Content-Type: application/json" \
-d '{"jsonrpc":"2.0","method":"eth_getUncleCountByBlockHash","params":["0xb903239f8543d04b5dc1ba6579132b143087c68db1b2168786408fcbce568238"],"id":1}'