For self-hosting in your domain:

<script src='https://<your-domain>/external_api.js'></script>

meet.jit.si:

<script src='https://meet.jit.si/external_api.js'></script>

Creating the Jitsi Meet API object

For example:

const domain = 'meet.jit.si';

const options = {

    roomName: 'JitsiMeetAPIExample',

    width: 700,

    height: 700,

    parentNode: document.querySelector('#meet')

};

const api = new JitsiMeetExternalAPI(domain, options);