How To Enable or Add Immersive Mode in Lineage OS 14 or Other Nougat or Android 7 Roms in Notification Tiles | Root Needed | Hide Notification Bar and Navigation Bar

In my Lineage OS 14 official ROM, there is no notification tile for Immersive mode / Expanded desktop to hide the status bar or navigation key bar.

I can go to Settings-Display-Expanded desktop and enable it permanently or choose custom settings for a specific app. But, this is inconvenient.

Download an app called Nougat Quick Settings from the Google Play Store. 

And check Expanded desktop on the app. Then, in your full notification page (swipe down from status bar twice), select the pen/edit icon.
Go to the bottom and drag Immersive Mode tile from the bottom section to the top section.

Click on the tile and allow Root access. And select the option you want, Only hide status bar, or show status bar, hide all or show all.