qrcode.show is an easy code generator that can use either it's webgui or curl
# Basic QR generation via curl
curl qrcode.show -d https://google.com
# Make Wifi Network QR Code
# Replace SSID_NAME and WIFI_PASSWORD below
curl qrcode.show -d 'WIFI:S:SSID_NAME;T:WPA;P:WIFI_PASSWORD;;gene'