First Steps
Check the link
Ask the public RPC which chain it serves and compare the answer with the register.
One call
The method eth_chainId returns the chain id as hex. 0x1237 is 4663.
bash
curl -s -X POST https://rpc.mainnet.chain.robinhood.com \
-H "content-type: application/json" \
-d '{"jsonrpc":"2.0","id":1,"method":"eth_chainId","params":[]}'Expected reply
json
{"jsonrpc":"2.0","id":1,"result":"0x1237"}On this site
The console on the home page sends the same call, plus two more, and prints whether the answer matches the register.