Duo's translation sounds off. If it is the vegetable, then we say "I like carrots." If you are talking about carrot flavor instead of vanilla flavor, then I guess, hypothetically, you could say "I like carrot."
You can't say "I like carrot" in English. Either "I like carrots" or "I like the carrot".
Another to the list; i really like carrots It's tedious trying to find the given right answer but totally understandable with the grammatical difference between Hindi and English!
I agree with the other comments here. It's extremely rare to use carrot as a non-count noun in English.