It is not working for me either. Tried on Windows 10 version 1903 and 1809.
Hey everyone,
Thanks for taking the time to reach out, and for your enthusiasm!
I can confirm that we are rolling out this feature to a small number of Chrome M74 users now, and that it will become more widely available in the near future.
The latest Chrome 74 update has added a flag that can enable dark mode for Android devices. You can follow the steps below to enable it on your Android device.
Go to the address and type chrome://flags.
Now search for “Android Chrome UI dark mode” and select Enabled.
Next up relaunch Chrome and go to Settings>Dark Mode to enable/disable dark mode.