Is it required for my video SDK app to be published so I can test it?

Video SDK
1

I have an application for video SDK, but not yet published:

Submit for review

Once you submit your app, Zoom will conduct a functional and security review of your app. On a successful review, your app will be published to the Zoom App Marketplace.

You are missing the following information:

1. Privacy policy URL (Links)
2. Terms of use URL (Links)
3. Support URL (Links)
4. Documentation URL (Links)
5. Endpoint URL (Deauthorization notification)

My question is should it be published to be able to test it out, because when I try the SDK keys and so on on a React application. I get this message:

Joining meeting timeout.

To join a meeting hosted by an external Zoom account, your SDK app has to be published on Zoom Marketplace. You can refer to Section 6.1 of Zoom's API License Terms of Use
2

It looks like you are trying to use a regular Zoom account to build with the Video SDK and not a Video SDK specific account. You can find details on how to set up a Video SDK development account here → Video SDK - Get credentials

Video SDK apps don’t need to be published to work, but they do need credentials from a different account type. Let me know if this helps.