Previously I got this reply Unable to access one zoom API end point - #4 by akona. Now I am refreshing an Access token through my code by calling the API. I am able to generate new Access token using Refresh token generated through my code within an hour but I am unable to refresh the Access token using the Refresh token after 1 hour.
To clarify, access_tokens are only valid for 1 hour. You will need to refresh the access_token using the associated refresh_token once the token expires (or before). You will also need to make sure you’re using the refresh_token that was originally returned along with the initial access_token.
Let me know if you have additional questions about this.