Please watch the video for step by step instruction on how to add an Enterprise plan code to your web app account:
Or you can follow the below step by step instructions:
Chrome Extension:
To add your Enterprise Plan code, click on the drop-down arrow next to your Profile Name:

This will open a menu where you can click See Plans:

A new browser tab will automatically open, taking you to our Web App.
Here you need to click on subscribe on the Enterprise Plan tab:

This will take you to the My Accounts page, where you can enter your Enterprise code:

Enter your code and click Apply code.
Web App:
To add your Enterprise plan code, click on the drop-down arrow next to your Profile Name:

This will open a menu, where you can click See Plans:

This will take you to our Plans page. Here you need to click on subscribe on the Enterprise Plan tab:

This will take you to the My Accounts page, where you can enter your Enterprise code:

Enter your code and click Apply code.