You can assign a regular key to systems in order to allow users (who have access to that system) get access to the assigned key.
Log on to the ePO - On-prem server as an administrator.
Click Menu → Data Protection → FRP Keys to open the FRP Keys page.
Select the key that you want to assign, then click Actions → Key Assignments → Assign to systems.
Select the required system or group, then click OK.
System assignment is completed successfully.