Regarding to send a message from Node red to Niagara 4 framework

General
20

Try this...

// Code of Function node

const incomingPayload = msg.payload; //save msg.payload before you destroy the msg object below
const username = "obixUser";
const password = "Wetec123456#@";
const ipAddress = "172.30.34.212";
const httpsPort = 443;
const authHash = Buffer.from(username + ":" + password).toString("base64");
const ordSlot = "/Supply$20Fan/NewValue";
const operation = "/set";

// create the message for the get request
msg = {
    "method": "POST",
    "url": "https://" + ipAddress + ":" + httpsPort + "/obix/config" + ordSlot + operation,
    "headers": {
        "Authorization": "Basic" + authHash,
        "Accept": "/"
    }

};

//ignore cert expired error
msg.rejectUnauthorized = false;

msg.payload = `<str val="${incomingPayload}" />`; //Use the saved value of msg.payload

return msg;