This can be done either manually, as needed, or by importing bulk using the Tags CSV import functionality. Therefore, you must configure all tags in the Designer. The S7 protocol does not support tag browsing.
To see and browse the tags, you need to create the tags manually as described in the Addressing section. Unlike other PLCs, but just like Modbus, Siemens devices do not support browsing, therefore you can not browse the tags by going to the OPC Connections > Quick Client in the Configure section of the Gateway. The Status will show as Disconnected and then Connected. The Devices page is displayed showing the Siemens device is successfully created and added to Ignition.
Scroll down and select OPC-UA Server > Devices.Go to the Configure section of the Gateway webpage.