People seeing Stories that contain a question can respond by tapping the sticker in the story, then type a question to ask in return if they wish. When you check your own story, you will now be able to see who asked you a question and what they said.
You’ll be able to tap a response from someone to share it and answer the question in your story, but when you do that, keep in mind that their photo and username will not be shown.
The ability to add question stickers to Stories is rolling out in the latest Instagram app on both the Android and iOS platforms. You should be looking for Instagram version 52 if you want to take advantage of the new feature.