How to get testnet credentials to use bit-coin core functions in Node.js.

{
    "Bitcoin": {
      "testnet": {
        "username": "name",
        "password": "sdaddf",
        "network": "regtest",
        "port": 18332 
      },
      "mainnet": {
        "username": "name",
        "password": "sadasd",
        "network": "mainnet",
        "port": 8332
      }
    }
}