I’m hoping to set up variables and expressions for my icon toggle button, so the outlined icon I swap with my placeholder will automatically go from outline to filled and vice versa when the icon button is selected or unselected.

In my current setup, if I swap the default outline icon with something else, the outline icon is kept as a preserved override, even when I change state from unselected to selected.

For example, if I swap my outline placeholder with an outline heart or an unchecked checkbox, how can I setup variables / variable prototype interactions so that when my toggle button goes from unselected to selected, the nested icon will go from outline to filled?

Any help is much appreciated.