How to recognize new subscribers and then change their status

Sorry for all the questions but I have built the bot but you say I have to be logged in as the Broadcaster to change VIP status. Do you mean such as:

const client = new tmi.Client({
options: { debug: true },
identity: {
username: <broadcaster’s Twitch Username>,
password: <broadcaster’s Twitch Password>
},
channels: [ process.env.CHANNEL_NAME ]
});

Is this what you mean?

And when I change the VIP status I would GET a user’s record and change the VIP bit - or is there an easier way?

Thanks