How to create custom plugin in image in-place editor for selecting focal point

[#1]

Hi

Is there any way to create new image in-place editor plugin to image component which will give us ability to select focal point on image and store the coordinates(x,y).

Below is the reference link where they have similar implementation in non AEM application -

https://designshack.net/articles/mobile/focal-point-intelligent-cropping-of-responsive-images/

Focal Point Crop | imgix Documentation

Using focal points to center images – Help

I want to give the flexibility to author to select the focal point same as the above links.

[#2]

I don't want the widget in dialog. I want a custom plugin similar to crop in image component. which allow author to select the focal point on the image.

I tried to create new one but getting this error - Uncaught TypeError: plugin.notifyPluginConfig is not a function at instanceGenerator.configurePluginsAndActions at instanceGenerator.start. Not sure where I can give the pluginConfig. or there a article where we can find how we can add the custom plugin in in-place editor edit bar.