See the article Joining a Test Meeting in the Zoom Help Center for more information about using the using the test Zoom meeting feature.

This option also will let you test your audio, screen sharing and chat. If you do have the desktop client installed, /test will open the test meeting in the client, just like it does for a normal meeting or webinar. It is a good choice if you plan to host or attend a meeting or webinar through Google Chrome. This option lets you test your audio and video even if you don't have the Zoom desktop client installed. This will launch a meeting where you are the only participant (you then can decide if you want to invite others). You also can launch a test Zoom meeting anytime at /test.

For instructions on testing video for your specific device, read How Do I Test My Video? in the Zoom Help Center.

Zoom mobile app on your smartphone or tablet.

Zoom Client for Meetings desktop application.

Make sure you have the correct software installed.

You can do that by checking manually or via a test meeting. It is a good idea to test your video in Zoom before a meeting or webinar.

Test zoom microphone before meeting