GIVING MyMarketingPass PARTNER ACCESS to your Instagram business page is easy! Once you hook up Creator Studio to your account, as long as you've given us Facebook access, you'll be good go:
Log into https://business.facebook.com/creatorstudio?tab=instagram_accounts
In the upper right of the screen, click the Add Instagram Account button.
Click 'Ok' on the notification about sharing access; a new window will open.
In this new window, log into your Instagram account; you may need to verify if 2-factor is turned on for your account.
Approve Creator Studio to post on your Instagram account.
Close this new window.
That's it! You did it :D