How to invite a user to business account using system-user access token on Facebook?

Question

I want to programmatically invite a user to a business account and I am using the API at https://developers.facebook.com/docs/marketing-api/business-manager/get-started#users-inviting-people. I have created a Facebook Login for Business app and also a configuration for system user with the required permissions. See the below screenshot showing the same

But, whenever I use the generated system-user access token, I always get the error

{
  'error': {
    'message': '(#10) You do not have permission to perform this action.', 
    'type': 'OAuthException', 
    'code': 10,
    'fbtrace_id': 'STRING'
  }
}

However, when I create a user access token, the API works.

How can I use the system-user access token to call the API? Is there any permission that I am missing or is it not supported at all?