Cannot read properties "addEventListener" when initialising new subscription

Hello,

i took the example directly from https://www.npmjs.com/package/@ringcentral/subscriptions and used it on my application.

import 'dotenv/config'

import {SDK} from '@ringcentral/sdk';
import {Subscriptions} from '@ringcentral/subscriptions';

// init
const sdk = new SDK({
    server: 'https://platform.devtest.ringcentral.com',
    clientId: process.env.RC_APP_KEY,
    clientSecret: process.env.RC_APP_SECRET
});
const platform = sdk.platform();
const subscriptions = new Subscriptions({
    sdk: sdk,
});

const main = async () => {
    // login
    await platform.login({
        'jwt': process.env.RC_LOGIN_JWT
    });

    // subscribe
    const subscription = subscriptions.createSubscription();
    subscription.on(subscription.events.notification, evt => {
        console.log(JSON.stringify(evt, null, 2));
    });
    await subscription
        .setEventFilters(['/restapi/v1.0/account/~/extension/~/message-store'])
        .register();

    // trigger events
    const r = await platform.get('/restapi/v1.0/account/~/extension/~');
    const ext = await r.json();
    platform.post('/restapi/v1.0/account/~/extension/~/company-pager', {
        from: {extensionId: ext.id},
        to: [{extensionId: ext.id}],
        text: 'Hello world!',
    });
};

main();

When trying to run, i get the error:

TypeError: Cannot read properties of undefined (reading 'addEventListener')
    at Subscription.setupWsEventListener (C:Projects
ingcentral-service
ode_modules@rc-exwslibsubscription.js:22:21)
    at new Subscription (C:Projects
ingcentral-service
ode_modules@rc-exwslibsubscription.js:19:14)
    at WebSocketExtension.subscribe (C:Projects
ingcentral-service
ode_modules@rc-exwslibindex.js:315:30)
    at Subscription.<anonymous> (C:Projects
ingcentral-service
ode_modules@ringcentralsubscriptionslibSubscriptions.js:89:58)
    at step (C:Projects
ingcentral-service
ode_modules@ringcentralsubscriptionslibSubscriptions.js:48:23)
    at Object.next (C:Projects
ingcentral-service
ode_modules@ringcentralsubscriptionslibSubscriptions.js:29:53)
    at fulfilled (C:Projects
ingcentral-service
ode_modules@ringcentralsubscriptionslibSubscriptions.js:20:58)
    at process.processTicksAndRejections (node:internal/process/task_queues:95:5)

Apparently the parameter 'ws' in /@rc-ex/ws/lib/subscription.js is undefined, resulting in an error when trying to add listeners.

Any help is appreciated

sdk version is 5.0.1

subscpriptions version is 5.0.1

Node version is v.18.17.1