Here’s how I did it.

1. Open Shortcuts App
2. Tap the + button in the top right corner.
3. Tap the Add Action Button.
4. Tap in the Search Field and Search “Set Silent Mode”.
5. At the top of the screen it will say Turn Silent Mode On.
   1. Tap the word “Turn” and select “Toggle”
   2. Go to the search bar at the bottom of the page and Search “Vibrate Device”
6. Tap Done in the top right hand corner.

Skip step 5b if you don’t want a vibration notification. Thats all.