Hello,
there are issues with OPC UA when the server is in the container. But, I am not aware of anything "special" when the part that is in the container is the client.

Applications based on QuickOPC, by default, create their own self-signed client certificate automatically, no coding needed.

Then, there is the issue of accepting the server certificate, if secure connection is to be used. Typically, what happens when you attempt to establish a secure connection from the client, is that the server certificate is rejected (not trusted), and its copy is placed, for convenience, into the folder (under the application directory) reserved for such certificates. If you then decide to trust the server, you can copy this certificate to the "trusted" certificate folder, and the connection will then work. This should be no different when done inside the container. Is this process what your question is about? If so, and it is not clear enough, let me know and I will provide further details. If your questions was about something else, please explain.

Best regards