If you look at the bottom of the call service node, you will see the valid options for the data section.
What is tells us is that the command must be in hexadecimal. I don’t use this component so I am unsure if the word normal just needs to be sent in hexadecimal. You can try
To add to what @Mikefila said: If your new to filling the data field, you can always use the “load example data” and it will probably format your data section correctly, but with mock-data. You would need to add the correct value for “event” yourself.