Not able to sync UI

I am trying to learn multiplayer in my project PlayCanvas | HTML5 Game Engine using photon and I was learning to sync things like UI for every player inside who joins. I tried multiple times to raise events for UI but was not able to achieve it.
I have created a simple 3D UI if we press the button it disables the image with the button itself and I want to sync both the button and image.

Can anyone tell me how to do it? I have shared my project link
It would be of great help :smiley: