How do I add an action to open the Settings app for each iOS and Android?

I would like to add an action to the screen where push notifications are set up that would take me to the notifications page of the settings app for each OS.

Perhaps a custom action is needed, but I would like to know what to write.

I would also like to use a separate custom function to determine whether push notifications are turned on or off and output them as text (on or off).