Lost Apple Watch
How do I find my lost Apple Watch because someone stole it
Question marked as
See this link for guidance on what to do if your watch is lost or stolen --> If your Apple Watch is lost or stolen - Apple Support
This presumes, it was signed into Find My and it can only be tracked if it is powered on and connected to a network. The sad reality is however, most stolen Apple Watches are never found or recovered. And Apple does not get involved in lost/stolen devices.
You should have filed a police report by now?