How to send notifications to an Android device from a PC via USB? I have seen Pushbullet, but it works over the internet
You can use adb shell and Notify4Scripts

source: https://forum.xda-developers.com/showpost.php?p=69859668&amp;postcount=18

date: 30th November 2016, 02:32 PM

Two years ago I was in need of a simple notification tool that could have been run by a command line in a script. So far the best I found was this thread and the tiny app made by corruptor64. That wasn't exactly what I was looking for so I finally decided to try to make the tool by myself. Starting from scratch (I am not an Android developer) in a few days of studying and developing I ended up with a working small app, that I named Notify4Scripts and I made it public only this past June, here on GitHub https://github.com/halnovemila/Notify4Scripts

Note that since the app is basically a service that has to be launched by the Android's shell "am" (activity manager) command, the Android system needs to be rooted first in order to be able to use such am command and have notify4scripts executed.