How can i lock screen without power button

[HackərKrishna]

How can i lock my my M51 screen without power button( if any gesture for double tap to lock screen)

[Vaishnavs]

I have installed one hand operations+ (App by Samsung, Available on galaxy store). I can do pretty much do everything with one hand using navigation gestures. Including switching apps, turning on torch, taking screenshots, Adjusting volume and brightness, locking screen, etc.
Do check it out.

[Stupidzz]

Same problem....in SAMSUNG GALAXY C9 PRO...

In my old phone(LENOVO VIBE P1 TURBO)..there was an option to lock my device like jzt turn my phone screen downwards...it will be locked...@SAMSUNG Please develop an option like that