One of the correct solutions is "I have not bracelets." This is an old form of speech and should probably be "I have no bracelets."
It accepted "I don't have bracelets", which is probably a better English translation than the more literal solution they give.
The Hebrew uses "צמידים" which is plural and means "bracelets". "A bracelet" is singular, and therefore not a correct answer. They accepted "I don't have bracelets" and should probably also accept "I don't have any bracelets".
A much more natural translation in English would be 'I don't have any bracelets' but I don't know if Duo would accept that (it might be regarded as literally wrong because of the word 'any' but it really is the more natural way of saying it in English).