need to restore HomePod. No labeling on device. How can I get a device code?

HomePod doesn't use a setup code. See the Press the top of HomePod to reset it section of Reset HomePod - Apple Support and follow the steps carefully as given.

tt2

HomePod doesn't work with certain types of Wi-Fi environment. From If you can’t set up HomePod - Apple Support:

• HomePod doesn't support public or subscription networks with sign-in requirements. These networks are often in places such as businesses, schools, dorms, apartments, hotels and shops. 

Check your router to see if you have a feature called something like Wireless or Client Access Security enabled. This blocks peer to peer communications for local wireless devices, and will prevent HomePod from working correctly. See also Use private Wi-Fi addresses on iPhone, iPad, iPod touch, and Apple Watch - Apple Support and turn off the Private Address option if currently enabled.

tt2