You need to use
OAuth2 Class to get an AccessToken.
Once you have a Token you can call any of the Listed Methods.
For example:
API Reference for /api-reference/chat/methods
marketplace.zoom.us
You need to add a Authorization Header using "Bearer xxxx" where xxx is your AccessToken
The rest is described in the Documentation. While browsing a bit there i see that they do provide a "TestTool" too. So you can easy build a test there and see how the call must be done.