Hi @Lisa0704 , welcome to the B&R Community! I would add that there is an existing B&R Community post that walks through how to set up PLC-to-PLC OPC UA communication, maybe it is useful for you. Here is the link: How to communicate two controllers thought OPC UA
Note: that this is using AS/AR 4.x, which is not the most recent version of Automation Studio and Automation Runtime (AS/AR 6). While the OPC UA Any device portion is similar to AS/AR 6, there are some significant differences in the configuration of the OPC UA server in AS 6 that need to be taken into account.