// Request
curl https://arbitrum.blockpi.network/v1/rpc/your-rpc-key -X POST -H "Content-Type: application/json" --data '{"jsonrpc":"2.0","method":"eth_getBlockTransactionCountByHash","params":["0x3b32dd164f1eb2b1f925c214e7180bf35280cf233a01f7e3a5d70203912e6808"],"id":1}'
// Result
{
"jsonrpc": "2.0",
"id": 1,
"result": "0x2"
}