How to change the brightness of the Galaxy A10s flashlight

I saw how this application ([Cardiograph](https://play.google.com/store/apps/details?id=com.macropinch.hydra.android)) uses a bright flashlight, and then it switches to a dim one. The phone itself (Samsung Galaxy A10s) does not have a built-in flash brightness control, and there is no root either. So, how can you adjust the power of a flashlight, what applications are there for this (maybe even somehow through Termux)? Samsung Galaxy A10s phone, Android 11, all updates installed. [Video](https://youtu.be/B1TyDSkukOs)