Error message probably due to wrong type of account

I’m getting this error:
Error: Access Token is not valid or has expired. Feed will not update.
API error 100: Unsupported request – method type: get

I’m trying to reauthorize with a Personal insta account – however, when I look in the account, I think it might be a business account.

Could you help me understand how to authorize it as a business account? I don’t have access to the client’s Facebook to authorize that way. What access would I need? Is it that they need to share access to their Facebook page with me, or do I need their personal Facebook login to make this work?

Could you please help me understand this sort of arcane authentication process or point me to a resource that would show me *how* they can grant me enough access to authenticate this as a business account.