The feature flag "Disable or enable gateways and drivers" should be turned on. This requires a full metadata update.
Driver is a new object type added since MicroStrategy 2021 Update 8. Each driver object is corresponding to a physical driver (used to fetch data from data sources) installed in IServer. By changing the "enabled" status of a driver object, customer can control whehter to block usage of corresponding physical driver or not.
This page contains a summary of REST APIs of "drivers" endpoint. You can use REST API requests to retrieve a driver's definition or retrieve a list of drivers' definitions or update a driver's definition.