Found the answer to my issue - follow these steps.
1. Open a pdf and click on Protect.
2. Select More Options from the menu
3. Select Security Properties
4. From the Security Method field - select "Adobe Experience Manager Document Security” and press Yes to add server info.
5. From the Server Settings screen - press the New button and add your server info.
6. Press the Connect to this server button upon entering all the information.
7. Press Ok within the confirmation screen.