Using an element of a document tag datatype

Firstly sorry if this is a very basic issue.

I currently have a connection to a MQTT client (shelly 1)

I am using this shelly UDT.

Connection is established and i can trigger the shelly relay.

When i goto display the status or state of the relay.

the tag .value returns the following expression.

{ "ison": true, "has_timer": false, "timer_started": 0, "timer_duration": 0, "timer_remaining": 0, "source": "http" }

This is due to the tag data type being document

I have a hunch i should be using the expression tab. I put it into tag tab to view the tag binding preview below.

How do i use just one element("ison") of the document/expression to trigger green/red

There are multiple way to achieve this , one example would be
Use Script Transform value["ison"] followed by Map transform to map Boolean value.

This works perfect. Thank you