If you want to add your own script which should update itself whenever the resolution changes, implement IResolutionDependency.

You will then need to implement a method called "OnResolutionChanged()". Trigger your update stuff there. 

Note that you probably also need to perform the same logic in your OnEnable() method to make sure it is also calculated when the scene is opened and the resolution has not changed.

The Resolution Monitor will update your MonoBehaviour then automatically when the resolution changed.

Here is an example.