Difficulties setting up freesync

So few days ago I’ve replaced my old 1080p 22" 60Hz Iiyama monitor to 27" 1440p 165Hz gaming monitor with Freesync feature. My GPU is Radeon RX580 8GB so both monitor and GPU are Freesync capable. I’ve turned on Freesync via monitor’s OSD but it doesn’t seem to work. So I started to look for solution online. Found this thread here: How to enable FreeSync on amdgpu? aswell as this: Variable refresh rate - ArchWiki
and this:
AMDGPU - ArchWiki

I did create a file: /etc/X11/xorg.conf.d/20-amdgpu.conf as explained for manual configuration:

Section "Device"
     Identifier "AMD"
     Driver "amdgpu"
     Option "VariableRefresh" "true"

After reboot nothing changed the output of

systool -vm amdgpu

still shows:

freesync_video = "0"

Can someone help me explaining how to activate it, please?