Intelligent Voice PCI redaction for Zendesk Talk is licensed for each Zendesk Talk agent. If some of your agents do not have Zendesk Talk you can reduce the number of agents for this app.
To do this you will need to create a group which contains all your Zendesk Talk agents, and restrict the visibility of the app to just this group. This will then reduce the number of agents you are billed for to the number of agents in the group.
This can be done before installing Intelligent Voice PCI redaction from the marketplace, or applied to the app after installation
For more details on app visibility see this Zendesk article: Restricting the visibility of an app by group
Please contact us for assistance with large or complex setups.