Install usbguard Package

---
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: master
  name: 75-master-usbguard-install
spec:
  config:
    ignition:
      version: 3.1.0
  extensions:
    - usbguard

This will install the usbguard package in all the nodes labeled with the "master" role.

Note that this needs to be done for each MachineConfigPool

For more information on how to configure nodes with the Machine Config Operator see the relevant documentation.