Overview
A permissions error occurs when the person trying to sign up does not have the required level of access to the Facebook Business Manager for the page you are trying to sign up.
Why Does This Happen?
A common misconception is that being an Admin of a Facebook Page is enough. However, unless you have Full Control of the Facebook Business Manager account the page is assigned to, you will not be able to complete the sign-up process.
How to Fix This Issue
Forward the Portal Link
Share the sign-up link with someone who has Full Control of the Meta Business Account.Complete the Setup
Once they complete the onboarding steps, any user with access to the Facebook Page can use the portal.
How to Check If You Have Full Control
Navigate to Users > People.
Check the Business Portfolio Access column to confirm if you have Full Control.