@julie_priest as others have mentioned, the Lumin devices are Ethernet-only. You must use an Ethernet cable. Fuzztone's link is broken, but I think he was linking to something like the TP-Link AC750 which we've also used many times.
The Lumin will use DHCP to acquire all of the network information, at which point the Lumin app on your iOS, Android, or M1 Mac computer will be able to find it. You can also use any other OpenHome compatible apps, like Linn Kazoo, and it is also supports several other protocols if you want to use other apps.