Video SDK Zoom Toolkit

we tring to get Paticipation when join to session 

function joinSession() {
    debugger;
    // 1. Add the event listener BEFORE joining
    window.addEventListener('onSessionJoined', (event) => {
        console.log('Session joined event received');
        // This is the underlying Video SDK Client
        const client = event.detail.client;

        // Sync your initial user count
        userCount = client.getAllUser().length;
        checkParticipantCount();

        // 2. Real-time participation listeners
        client.on('user-added', (payload) => {
            userCount = client.getAllUser().length;
            console.log('User Joined:', payload[0].displayName);
            checkParticipantCount(); // This stops your countdown
        });

        client.on('user-removed', (payload) => {
            userCount = client.getAllUser().length;
            console.log('User Left. Remaining:', userCount);
        });
    });

    // 3. Now join the session
    uitoolkit.joinSession(sessionContainer, config);
    timerId = setInterval(countdown, 1000);
    uitoolkit.onSessionClosed(sessionClosed);
}

Error 

uncaught TypeError: uitoolkit.vsdkSubscribe is not a function
    at joinSession (scripts.js:414:15)
    at Object.success (scripts.js:384:17)
    at c (lib.vendor.bundle.js:1:27603)
    at Object.fireWith [as resolveWith] (lib.vendor.bundle.js:1:28347)
    at u (lib.vendor.bundle.js:1:78549)
    at XMLHttpRequest.<anonymous> (lib.vendor.bundle.js:1:80876)
    at XMLHttpRequest.We (videosdk-ui-toolkit.js:2:11547)
    at v.invokeTask (videosdk-ui-toolkit.js:2:7294)
    at L.runTask (videosdk-ui-toolkit.js:2:2674)
    at m.invokeTask [as invoke] (videosdk-ui-toolkit.js:2:8345)