Google Home connectiviy issue

Hi! I've recently got an Ikea Symfonisk Bookshelf because of the great design and quality hoping to use it along with my google chromecast and assistant in order to form a streaming group with each one of them in different rooms. However, I can't find any way to sync the products since Sonos doesn't have the voice services available in my country. The thing is that I'm only really interested in using all three devices for streaming music together so I'm looking for a way to be able to add the Sonos Symfonisk in my Google Home app only as an additional speaker, I don't need the voice service at all. Does anyone know any solution? I'm unfortunately considering returning the Symfonisk unless I can find a way to solve this problem.