The Giant Board uses u-boot overlays to load the device configurations at boot. This makes it easy to enable and disable hardware being used with Linux drivers instead of CircuitPython.
The easiest way to change the overlay options its to edit the uEnv.txt text file using this command
sudo nano /boot/uboot/uEnv.txt
When the file opens, it should look like this

Make sure to uncomment the line enable_uboot_overlays=1
this allows overlays to load on boot:
# enable u-boot overlays
enable_uboot_overlays=1
You’ll then want to add the line /overlays/GB-WIFI-FEATHERWING.dtbo to the first dtboverlay variable. Which should look like the image below.

After completing the steps above, we can now go over how to connect to a WiFi network using connman, which is pre-installed.
Once the reboot is complete, proceed to login and then type the command:
sudo su
Once in root, you can now type the following command chaning testing out for your own WiFi SSID
wpa_passphrase "testing" >> /etc/wpa_supplicant/wpa_supplicant.conf
You can then type your WiFi password in. There wont be a prompt to asking for the password, but will take the password once enter is pressed.
Once you have entered your password, you can then logout of the root user by typing:
exit
You should now be back on the debian user.
The reason for doing this is to make sure your WiFi password is not stored in plain text on your device.
Its recommended to enter the following command and remove your plain text password from the file, it should be commented out.
sudo nano /etc/wpa_supplicant/wpa_supplicant.conf
Ctrl + x to exit and hit enter to save the file.
In the next step you’ll need to edit the interfaces file with the command below so you can add some basic networking information.
sudo nano /etc/network/interfaces
Just below the other lines that are in the file, you can paste in this basic DHCP networking configuration.
auto wlan0
iface wlan0 inet dhcp
wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf
Ctrl + x to exit and hit enter to save the file.
You’ll then need to reboot one more time to easily reload the new configuration. Once rebooted it might take a minute or 2 for initial setup. You can test if you are connected to the internet using the ping command.
ping -c 4 8.8.8.8
You should see a response back if everything is setup properly.