Instagram story ads are the way of promotion on Instagram. Engagement is very important factor in the growth of a brand in social media. Your reach is important.
Instagram provides the promotion facility in their app that you can promote your work. You can pick your any story and promote it. Now it will be showcase on other user’s accounts too who are not following you on Instagram.
‘Promotion’ option is available on the left corner of the ‘edit profile’ option in profile tab. You can promote your post and story there. You have to payment for the promotions.