var mqtt = require('mqtt'); that shows syntax error - node.js

Question

i am following this tutorial regardign saving data to database using mqtt to mysql sensor to mysql via mqtt where i am at the app_mqtt.js part where i try to follow the exact same thing to create the js file but when i try to run it via python, it shows an error of :
File "app_mqtt.js", line 1
var mqtt = require('mqtt');
^
SyntaxError: invalid syntax
I have already the mqtt via npm i mqtt and npm install mqtt --save yet it still have such an error, i really need help in this. Thank you.
var mqtt = require('mqtt');
var Topic = '#'; //subscribe to all topics
var Broker_URL = 'mqtt://192.168.1.123';
var options = {
clientId: 'MyMQTT',
port: 1883,
keepalive : 60
};
var client = mqtt.connect(Broker_URL, options);
client.on('connect', mqtt_connect);
client.on('reconnect', mqtt_reconnect);
client.on('error', mqtt_error);
client.on('message', mqtt_messsageReceived);
client.on('close', mqtt_close);
function mqtt_connect()
{
console.log("Connecting MQTT");
client.subscribe(Topic, mqtt_subscribe);
}
function mqtt_subscribe(err, granted)
{
console.log("Subscribed to " + Topic);
if (err) {console.log(err);}
}
function mqtt_reconnect(err)
{
console.log("Reconnect MQTT");
if (err) {console.log(err);}
client = mqtt.connect(Broker_URL, options);
}
function mqtt_error(err)
{
console.log("Error!");
if (err) {console.log(err);}
}
function after_publish()
{
//do nothing
}
function mqtt_messsageReceived(topic, message, packet)
{
console.log('Topic=' + topic + ' Message=' + message);
}
function mqtt_close()
{
console.log("Close MQTT");
}

Answer 1

As per your code , it shows fine.
1) Try to restart the server.
2) check your code to this code
npm i mqtt --save
var mqtt = require('mqtt')
var client = mqtt.connect('mqtt://{Your connection string}')
client.on('connect', function () {
client.subscribe('presence', function (err) {
if (!err) {
client.publish('presence', 'Hello mqtt')
}
})
})
client.on('message', function (topic, message) {
// message is Buffer
console.log(message.toString())
client.end()
})
3) At last , re-install the package.
Note: If still issue , please share your code. So I can debug it.