How do I make a button to lock & turn off screen (like Soft Lock Screen)

I want something exactly like Soft Lock Screen, which, once I tap on it, will turn off the screen and lock the phone.

Only thing is, I want that button to sit in the Slide Down Notification panel all the time. Whenever I tap on it inside the Slide Down Notification Panel, it should turn off the screen.

Please guide me in the correct direction! :cyclops:

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