docs(react-sdk): add disclaimer to create livestream call before clic…

…king Join Call (#1062)

packages/react-sdk/docusaurus/docs/React/02-tutorials/03-livestream.mdx

@@ -216,7 +216,7 @@ Upon running your app, you will be greeted with an interface that looks like thi
 Stream uses a technology called SFU cascading to replicate your livestream over different SFUs around the world.
 This makes it possible to reach a large audience in realtime.
 
-Now let's press **Start Livestream** in your new app and click the **Join Call** button below to watch your livestream in another tab in your browser:
+Now let's press **Start Livestream** in your new app and click the **Join Call** button below to watch your livestream in another tab in your browser. Please, make sure the call is created using the credentials from [section Step 2](#step-2---broadcast-a-livestream-from-your-device) before you click `Join Call`:
 
 <TokenSnippet sampleApp="livestream" displayStyle="join" />