HOW TO PLAY YOUTUBE IN BACKGROUND

This tricks only for working on funtouch os 14 if you don't have funntouch os 14 in your device first update your andriod andriod version. Go to settings→system update→checking for updates.

If you have Funtouch OS 14 this steps for you

1. open youtube and play anyting
2. click on smart sidebar(on right screen edage)
3. click on Background stream   

Now you can see your youtube videos play in background and press exit remove background steam.

Smart Sidebar feature path: Settings – Shortcuts & accessibility - Smart sidebar.