curl --request PUT \
  --url https://realtime.replace-me.example.com/custommeters/{customMeterId} \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "utilityAccountNumber": "6789",
  "accountId": 500,
  "submeterAccountId": null,
  "meterNumber": "5678",
  "type": "realtime",
  "multiplier": 100,
  "readingsPerHour": 18,
  "name": "Meter: 5678",
  "timezone": "UTC",
  "displayTimezone": "UTC",
  "meterProvider": "OBVIUS_METER",
  "energyUnit": "MW",
  "energyUnitCode": null,
  "isCumulative": false,
  "additionalSettings": {
    "password": "********",
    "serialNumber": "001ABCDE",
    "device": "2",
    "readingColumns": "8",
    "timestampColumn": 1
  },
  "shiftCumulativeReadings": false,
  "shiftReadings": false,
  "cumulative": false
}
'

const options = {
  method: 'PUT',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    utilityAccountNumber: '6789',
    accountId: 500,
    submeterAccountId: null,
    meterNumber: '5678',
    type: 'realtime',
    multiplier: 100,
    readingsPerHour: 18,
    name: 'Meter: 5678',
    timezone: 'UTC',
    displayTimezone: 'UTC',
    meterProvider: 'OBVIUS_METER',
    energyUnit: 'MW',
    energyUnitCode: null,
    isCumulative: false,
    additionalSettings: {
      password: '********',
      serialNumber: '001ABCDE',
      device: '2',
      readingColumns: '8',
      timestampColumn: 1
    },
    shiftCumulativeReadings: false,
    shiftReadings: false,
    cumulative: false
  })
};

fetch('https://realtime.replace-me.example.com/custommeters/{customMeterId}', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

import requests

url = "https://realtime.replace-me.example.com/custommeters/{customMeterId}"

payload = {
    "utilityAccountNumber": "6789",
    "accountId": 500,
    "submeterAccountId": None,
    "meterNumber": "5678",
    "type": "realtime",
    "multiplier": 100,
    "readingsPerHour": 18,
    "name": "Meter: 5678",
    "timezone": "UTC",
    "displayTimezone": "UTC",
    "meterProvider": "OBVIUS_METER",
    "energyUnit": "MW",
    "energyUnitCode": None,
    "isCumulative": False,
    "additionalSettings": {
        "password": "********",
        "serialNumber": "001ABCDE",
        "device": "2",
        "readingColumns": "8",
        "timestampColumn": 1
    },
    "shiftCumulativeReadings": False,
    "shiftReadings": False,
    "cumulative": False
}
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.put(url, json=payload, headers=headers)

print(response.text)

{
  "id": 12406,
  "utilityAccountNumber": "6789",
  "accountId": 500,
  "meterNumber": "5678",
  "type": "realtime",
  "multiplier": 100,
  "readingsPerHour": 18,
  "name": "Meter: 5678",
  "timezone": "UTC",
  "displayTimezone": "UTC",
  "commodity": "electric",
  "meterProvider": "OBVIUS_METER",
  "sourceCategory": "CONSUMPTION",
  "isCumulative": false,
  "additionalSettings": {
    "password": "********",
    "serialNumber": "001ABCDE",
    "device": "2",
    "readingColumns": "8",
    "timestampColumn": 1
  },
  "cumulative": false,
  "virtualMeter": false,
  "energyUnitCode": "KWH",
  "energyUnit": "kWh"
}