A Business Manager can claim Instagram Accounts that belong to the business. This enables a business to easily manage Instagram accounts and ad accounts used for these Instagram accounts. See Instagram Ads Setup for more information
You cannot manage roles for Instagram accounts owned by a business. You can only run ads for Instagram accounts with access to the ad accounts linked to the Instagram accounts.
To claim an Instagram account for your business, you must use the Business Manager UI. See Add an Instagram Account to your Buisness Portfolio in Business Manager.
You can use the API to manage relationship between a business and an Instagram account. See Guides. You can:
There are also APIs to manage the relationship between ad accounts and Instagram accounts. See Instagram Ads API.