Try the troubleshooting steps at the bottom if you encounter any issues before contacting support.
Go to your browser's extensions page and enable Developer Mode at the top right corner.
Add the Tampermonkey browser extension from the official website.
Go to extensions page → Find Tampermonkey → Click Details → Scroll down → Enable Allow User Scripts
Go to your Edgenuity dashboard. The Nexus menu will appear asking for your license key. Paste the entire key (including "Nexus-") and you're all set!
Menu not showing up?
Enable Developer Mode in your browser's extensions page, then restart your browser and device.