I like to be able to send test push notifications to make sure my settings are working for all my plex users / devices.
What kind of notification?
The ones that notify you when new episodes or movies are added
Have you considered simply adding a test file? Even a text file named as a video should do that trick.
I could, but it much easier with the press of a button, especially when visiting familie and testing there devices, away from home. which is why im asking 
I know this is not exactly what you are looking for but you can send a message by clicking on the share option on any media then select anyone that is a “friend” ( which may be different than who you gave server access to).
Your family of course would need to have the appropriate notification enabled in the mobile app
