If you don't want other students to see your name and score in the leaderboard, please go to your student account page in lingu.com.
Click on your name in the upper right corner, and click on Settings
Click Personal Information
Scroll down to "Privacy settings"
Toggle on "Hide my profile in leaderboard". Changes are saved automatically.
Next time you open a lesson, you will see your own name in the leaderboard, however other students will not see your name there.
Your score will not be considered when this setting is turned on. Which means, even if you see your name in the top of the list, for example the 1st place, other students will cannot see you and they will see the name on the 2nd place ranked as number 1.