Hello Anais.

This happens if you missed something when creating the new app. I faced the same issue because I forgot to add the scopes, so please go over these points:

1. Make sure you're on the correct App:

2. Under the "Information" step in Zoom, there are three mandatory fields:

In the Basic Information section, you need to add the Company Name
In the Developer Contact Information add your Name
Also, in the Developer Contact Information, add your email address and click “Continue”.

3. The "Feature" section can be skipped.

4. Under "Scopes" step, you need to add the following scopes:

• View all user meetings;
• View and manage all user meetings;
• View all user information;
• View users’ information and manage users.

Even though these scopes are listed in Zoom, copying and pasting “View all user meetings” (for example) won’t return any results, so just search for one keyword from the scopes above. In the previous example, searching for “meeting” returned the scope we want to activate.

Also, once you select a certain scope, you can search for another one, and then for another one until all 4 are selected. Only then should you click on the “Done” button in the bottom right of the Scopes popup.

5. Make sure that the app is activated in the "Activation" step.

I'm attaching a short screen recording that may help you with this, but please let me know if you're still having issues with the integration.