1. At the top-right corner of the menu, click on the "hamburger" icon to view the available options:
2. Click Save.
3. A prompt will then pop up informing you about the lab duration. Select Yes, save my lab in order to confirm your action.
Your lab is now saved and has stored the progress you've made so far.
4. At the last prompt, press the Close Window button.
5. The next time you wish to resume the saved lab from where you left off, just sign in to your eLearning account (https://ondemand.defensityone.com) and click on the associated course.
6. Once the course opens, from the left menu (module section) click on CDFE lab (It can be any other lab). In the middle pane you will see the RESUME LAB button. Click on it to launch your saved lab.