wpa_passphrase <ESSID> <passphrase> >> /etc/wpa_supplicant/wpa_supplicant-wlan0.conf
Then, the sergice service should be enabled on the ''wlan0'' interface for instructing let systemd to start it using the (just) created configuration file <code>wpa_supplicant-wlan0.conf</code>:
systemctl enable wpa_supplicant@wlan0