Hello @minjun ,
Please let us know if you need further help in this matter.
To do most things on your HoloLens, you have to be connected to a network, at least for the initial setup. Please also visit this hololens discussion and this news to get more info. Dynamics 365 Guide example scenario page.
The first time you use your HoloLens, you'll be guided through connecting to a Wi-Fi network. If you have trouble connecting to Wi-Fi during setup, make sure that your network is either an open, password-protected network or a captive portal network. Make sure that the network doesn't require you to use a certificate to connect. After setup, you can connect to other types of Wi-Fi networks.
On HoloLens 2 devices a user may also use a USB-C to Ethernet adapter to connect directly to Wi-Fi to help assist in setting up the device. Once the device has been set up a user may continue to user the adapter or they may disconnect the device from the adapter and connect to wi-fi after set up.