If you are using Sonos One or Sonos Beam in Singapore, you will be happy to know that as of two days ago (6th November 2019), Google Assistant is available for all Sonos users in Singapore.

Previously, if you want to use Amazon Alexa or Google Assistant, you will need to go to your Sonos profile and change your country to the United States, as mentioned in my Sonos One blog post.

Sonos - SettingsSonos - Services
Sonos – Settings