No; both are correct.
Plural suffixes such as -mey are generally optional in Klingon, though it will often be clearer if you do use them.
But e.g. qoq vIlegh can mean either "I see the robot" or "I see the robots" -- qoq by itself can be plural even without an ending.
If you have read the Tips & Notes for this Skill, you might have seen a special note on robots. If you have not been reading the Tips & Notes, I would like to ask that you review those so we don’t have to continuously repeat the information that we have explained there.
If you are doing the course on iOS or Android, you may not currently be able to access the Tips & Notes through the app. To access the Tips & Notes, you might have to access the course using a web browser at https://www.duolingo.com/. You can still do it on your mobile device, but you will have to use the web browser instead of the app (or you can do it from a computer). When you click on a Skill, it will expand to reveal a Start button and a light bulb.
If you click on the light bulb it will reveal the Tips & Notes and give you a detailed explanation of the grammar that is introduced in that Skill. If you have questions after reading the Tips & Notes for this or future Skills, then please return to the forum to ask your question, explaining what you didn’t understand or what seems contradictory to you.