$ nano ~/.config/autostart/autoChromium.desktop
Add:
[Desktop Entry]
Type=Application
Exec=/usr/bin/chromium-browser --noerrdialogs --disable-session-crashed-bubble --disable-infobars --incognito --kiosk http://www.website.com
Hidden=false
X-GNOME-Autostart-enabled=true
Name[en_US]=AutoChromium
Name=AutoChromium
Comment=Start Chromium when GNOME starts