How to attach light to part of game object made from psb? 2D

There is a 2D game object made from psb file, and I need to attach light to one of the sprites (stem). For now light is a child of a stem. When moving entire game object - lite is following. But when bending the stem with the rig animation - lights isn’t following.
I’v tried adding Parent Constraint to the light, adding light as a child of a bone, adding some other sprite (with a light) as a child of the stem - it doesn’t follow the stem bend when i’m rotating bones.
Thank you!

You would create a new gameobject and drag the character and the light into it then add the moving script to the gameobject and not the character gameobject. @KateSu