How to Change default WIFI setting of DSGW-210

The gateway default WIFI setting of DSGW-210 is in AP mode.

Can I change it to client mode to connect to my existing WIFI network?

Where to change the setting?

Currently the gateway only enables the AP mode by default, if you would like to enable the station mode, please log in to the gateway using ssh and with wpa_suppclient to enable it.

Could you provide some more details please.
I have installed and configured wpa_supplicant and I am able to connect to Wifi with the manual command: wpa_supplicant -B -d -i wlan1 -c /etc/wpa_supplicant.conf
but I want to set the client mode and automatic connection as client with my network as standard after boot. How can I make these settings with the debian image?
Thanks a lot!

you can add the commands to the startup script. For example, /usr/bin/reapp.sh