If your brand of TV isn't listed, this will be a case of trial and error to see if another manufacturer uses the same or similar codes to control volume, power, and input.
To be clear, you do not need to setup these settings for the voice remote to function. You can skip this part of the setup and the voice remote will otherwise work just fine, you just won't be able to control your TV's volume, power, or change inputs using the Chromecast remote. You would need to use your standard TV remote instead.
Yes, I know I only need it for the Volume and Power controls, so I can live without it.
Yet, I don't see how I can reasonably do "trial and error" when there are hundreds, maybe thousands, of options to try.
@moddyfir, it looks like your TV isn't compatible with the Voice Remote. Please take note that although there are TV brands that can be set up for Chromecast with Google TV however, not pairable/compatible with the Voice Remote.
You may try to choose a different brand from the list, which in your view has the same country of manufacturer as the TV. You may also search for TV remote codes online and see if any other brand matches the same code as Muller, and select that other brand instead. However, please be informed that this step may or may not work. You can check this link for more information about requirements for Chromecast devices.
We'll also take this as feedback as we are always looking for ways to improve our products. You can also send feedback via Google TV. Here's how.
Hope this helps.