For an OPC UA application to coexist and communicate properly in the operating system and in the OPC UA ecosystem, it needs to fulfill certain conditions, and integrate in the prescribed way with the environment. From the code, this what the OPC UA Application object offers. There are aspects of most OPC UA applications that need to be administered by the end user. In Windows desktop application, OPC Data Client offers a ready-made dialog for this, and you can integrate this dialog into your application.
The "Administer OPC UA Application" dialog allows:
The dialog can be integrated into your application in following ways:
With any of the above methods, you can specify whether the end user will be allowed to change the password to the private key of the own application certificate. Changing the private key password should be disallowed if your application logic maintains the password itself, or if you have not implemented the logic to persist the private key password (if the user was allowed to change the private but your application won't persist it, the passowrd will be incorrect next time the application is run, and it will not work).
For the end-user documentation, i.e. how the user of your application can operate the dialog, see Dialog: Administer OPC UA Application.