Facebook began the process of updating the Instagram API to the Instagram Graph API, built on the Facebook Graph API. This change helps businesses manage their organic presence more effectively.
From 30.01.2018 Instagram introducing new features to the API, such as allowing businesses to schedule photo posts, view posts they've been tagged in and view other business profiles. You can't schedule videos, carousels and Instagram stories.
To get started with scheduling posts, you can work with one of Facebook Marketing Partners or Instagram Partners.