OH3 Transform toggle ON/OFF value to OFF/HEAT compatible with hvacMode Tado Binding

Hello, I am at the first experiences with OpenHAB 3.0
I have corrected binding my Tado devices to OpenHAB. I created the devices and inserted into the model.
I would like to control the hvacMode channel value via a switch item. I have created the Item and linked it with hvacMode channel. I have change “Default List Item Widget Metadata” to oh-toggle-item for change UI from combobox values to switch on/off.

When I turn on the switch I see from the logs an exception because the Tado binding module does not recognize the string “ON”. At the toggle event, I would need to transform the OFF / ON values into the corresponding OFF / HEAD values. Can you suggest me in detail how to perform this action ?