How can I add an RPC for the second blockchain on the same subnet

[HelmiTrabelsi]

Describe the bug
I have two blockchains running on the same subnet. However, when I start the node, there is only one RPC endpoint available for one of the blockchains.

I can't find in the documentation or discord how I can add a second RPC endpoint. should it be in the subnet config file?
Is it necessary to use a different port number?

This my config file

{
    "skip-upgrade-check": true,
    "api-admin-enabled": true,
    "eth-apis": [
        "eth",
        "eth-filter",
        "net",
        "web3",
        "internal-eth",
        "internal-blockchain",
        "internal-transaction",
        "debug-tracer"
    ],
    "http-host": "",
    "data-dir": "/home/ubuntu",
    "http-port": 9123,
    "network-id": "fuji",
    "public-ip": "X.X.X.X",
    "staking-port": X,
    "state-sync-enabled": true,
    "track-subnets": "X"
}

[j-woodlee]

Hey, this is random but I am trying to run two blockchains on 1 subnet as well, and you might be able to assist with my issue #1780. If you feel you know the answer to my question feel free to respond in there, thank you!