Offhand Dynamic Lights Add-on 1.21+

Darkness is no longer a problem when you have light in your hand. With the mod Offhand Dynamic Lights, the light moves with you, illuminating dungeons, forests, and mines in Minecraft PE. Torches, Lanterns, and other lighting blocks now work right in your hand—without installation and extra movements.

This is a simple way to make the gameplay much more comfortable. Crouch twice in 1 second to use a Torch in your left hand.