taskbar : callbacks to close app on click ?

[whodisp]

Hello, I couldn't find a way to close an app in the taskbar widget using callbacks, I thought about using cmd taskkill but can't find a way to target the selected app each time.
I couldn't find anything in the wiki nor discussions and I'm pretty illiterate when it come to programming so i'm sorry if there was an obvious answer :)

What i would like :

taskbar:
type: "yasb.taskbar.TaskbarWidget"
options:
animation:
enabled: true
icon_size: 16
callbacks:
on_left: "magic words that kill the app i'm left clicking''

Thanks for any suggestion !

[amnweb]

This widget does not have close app as a callbacks method. I will check if I can add this

[amnweb]

Updated: close_app has been added as a callback to close the currently focused app.