Where does one place WIIM in flow?

[MikeWilson]

Looking at WIIM devices. A recent ROON newsletter suggests adding a streamer. My Roon and two powered speakers are Ethernet connected to my router. Where in the setup would the streamer sit? The WIIM/Roon compatible ones I look at have an Ethernet in and a single optical output. Using Wi-Fi from the streamer to the speakers would downgrade sound quality (etc). How / where do I connect my speakers to this flow?
Thank you.