Modbus with OpenPLC

I want to write a value 1 to a openPLC ( with IP ) using modbus write node.
what values should I put in Unit-Id , Address , Add new Modbus client. As shown in the screenshot.

Thanks for the help in advance.

With warm regards.

At least some of the answers are in the info panel on the right hand side…

I have filled the following values from info i got from panel on right hand side.



I was able to configure the modbus write node and connect to the openPLC instance running on my localhost ( IP: and OS: linux ) successfully. however when I run the openPLC instance on Raspberry PI i am not able to connect my modbus write node. any suggestions ?
Both RPI and system where my node-red is running is pingable.