You will need an Instagram Professional Account to connect to the Platform. This Professional Account must also be CONNECTED to a Facebook Business Page to connect to the Platform.
To connect your Instagram to the Platform, verify these steps.
1. Convert your personal Instagram account to a Professional Account. This option will be done through INSTAGRAM, and you will see an option to choose which Facebook Business Page you want to connect to in the prompts.
Instagram Help Article - https://help.instagram.com/502981923235522/?helpref=uf_share
2. Your Instagram Professional Account must be connected to a Facebook Business Page that you are the admin of to connect to the Platform.
Instagram Help Article - https://help.instagram.com/570895513091465/?helpref=uf_share