Help with LG 4K HDR TV, Apple TV 4K, Samsung HW K470

[Voxels-Box]

Hi, new to the home audio section. 

TL;DR: how can I get my Apple TV remote to control volume of my Samsung HW K470 Soundbar?

Hardware:

LG 55” 4K TV with HDR Dolby Vision 2017

Apple TV 4K with Siri Remote

Samsung HW K470 HDMI soundbar 

Two 4K HDMI cables supporting HDMI-CEC and ARC. 

 

I’ve had the TV and Apple TV since 11/17, but since I’m moving into a smaller apartment, I’m downsizing from my nice 5.1 system to this sound bar (picked up for $130 but with no remote)

Two issues are present with the soundbar: 

1st. It’s not 4K compliant. My bad but I can live with that since it’s only a temporary solution. 

2nd. I don’t have a remote, and I’ve yet to get the Siri remote to adjust the volume properly. Presently it can only increase the volume. Does anyone know how I can get it working so that I can continue using a single remote? I found a replacement for the stock remote online but i would prefer to not need it. 

 

Thank you!