Controlling light intensity via umg slider from clients

[showpixel]

Hello dear community,

i would like to control a light wich is in my persistant level with a fader, BUT not only localy, also from the every client aswell.
I guess what i need is a way to control the same variable of the the same BP from all clients.
I can control the lightintensity already, but it is only local. What am i missing here?

I have so far:

actor BP with a light in it

umg hud with a fader and a flasbutton

the level blueprint

Thanks in advance