To successfully post to an Instagram Business Profile, including direct publishing, the Instagram professional profile must be connected to a Facebook Page.
In a new browser tab, sign in to Facebook.
On the home page, click the Accounts icon in the top-right.

Select the Facebook Page you want to connect to Instagram.
In the left menu, open Settings.
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In Settings & Privacy, select Instagram.
Select Linked Accounts.
Select Connect Instagram and follow the prompts.
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