[JWT token] What it is used for?

I would like to use a token for unique videoconferences with external api but, i used like that:
You can also pass a jwt token to Jitsi Meet:

const options = {

jwt: ‘<jwt_token>’,
noSsl: false,

const api = new JitsiMeetExternalAPI(domain, options);

And it doesn’t work, i’m using it wrongly o what it is supose to happen?