To update the firmware on the Polk MagniFi Mini, you must be connected to the Internet via Wi-Fi or a cable using the built-in Ethernet port on the back of the MagniFi Mini (network cable not included). Hardwired connections via Ethernet do not need any additional setup.
If you plan to get updates via WiFi, you will need to download the Google Home app (free from Apple App Store or Google Play Store) and follow the directions to connect the MagniFi to your network. Once it's connected to the Internet, updates will occur automatically overnight.