Yes, there is a provision of replying to the guest reviews under the 'Reviews' section on Ingo-mmt Extranet. You can click on 'Reply Now' and post your reply. You might see 'Reply not required' against a few reviews, which means that the guest has just given the 'rating' and haven't put any 'text' in the review.
However,It is advisable to reply to all the reviews that you have recieved for your property.