Some questions about chain.json

[qyzxcswbll]

[
  {
    "name": "Testnet 8",
    "chainId": "test8",
    "apiUrl": "https://test8.api.onbloc.xyz/v1",
    "rpcUrl": "https://test8.onbloc.xyz:443",
    "indexerUrl": "https://test8.indexer.onbloc.xyz",
    "gnoWebUrl": "https://test8.testnets.gno.land"
  },
  {
    "name": "Staging",
    "chainId": "staging",
    "apiUrl": "https://staging.api.onbloc.xyz/v1",
    "rpcUrl": "https://rpc.gno.land:443",
    "indexerUrl": "https://indexer.onbloc.xyz",
    "gnoWebUrl": "https://gno.land"
  }
]

Where is the apiUrl? Is it open source?

[qyzxcswbll]

@jinoosss
Help me, please. Thank you very much.