How do I change the notification style in Zorin OS 17?
There is an extension thats is no longer worked on anymore, called "Panel OSD." This extension might do what you need.
If Panel OSD does not offer what you need, or does not work, you can try these others listed here...
In Zorin 18 you will be able to use this gnome extension:
I'm not sure what you would like to change. Can you please explain it more detailed?
Here is a gnome extension that works in Zorin 17: