add token provider example to node

docusaurus/video/docusaurus/docs/api/basics/authentication.mdx

@@ -233,6 +233,10 @@ client.create_token(user_id = user_id, expiration = exp)
 </TabItem>
 </Tabs>
 
+You need to provide the generated tokens to the client SDKs. Stream SDKs accept a token provider, that can be called to retrieve and renew tokens. You need to implement the token provider in your own application, this is usually an HTTP endpoint.
+
+Example [token provider for the Node SDK using Express](https://codesandbox.io/p/sandbox/stream-node-token-provider-example-f9cl27).
+
 ## Call tokens
 
 Call tokens contain a list of call IDs. If a user is authenticated with a call token, they can only access the specified calls. They are helpful if you want to limit call access, but you want to avoid managing call members (an example: a pay-pre-view link for livestreams, with hundreds of thousands of expected viewers).

docusaurus/video/docusaurus/docs/api/basics/get_started.mdx

@@ -59,6 +59,8 @@ You can optionally pass a timeout for the API requests, the default timeout is 3
 
 ```js
 import { StreamClient } from '@stream-io/node-sdk';
+// or
+// const { StreamClient } = require("@stream-io/node-sdk");
 
 const apiKey = '';
 const secret = '';