If you want to block apps in your organization, you can disable app usage from untrusted sources.
In Jamf School, navigate to Profiles in the sidebar.
Create a profile or edit an existing profile.
Ensure the Allow trusting new enterprise app authors option is disabled. This option is disabled by default in new profiles.
Note: If the app has already been installed and trusted, then you need to remove the enterprise profile from the device. Also keep in mind that this will also affect trusting your own enterprise apps, so if you want to distribute enterprise apps you have to make sure this option is enabled during the installation.