Access denied - insufficient permission

 Account Type is Business Plus

Request body:
curl -i -X POST "https://api.box.com/2.0/users" \

     -H "Authorization: Bearer <ACCESS_TOKEN>" \

     -H "Content-Type: application/json" \

     -d '{

       "name": "User Name",

       "is_platform_access_only": true

     }'

When I create a user using the API I get the below error.

create_user response
Array
(
    [type] => error
    [status] => 403
    [code] => access_denied_insufficient_permissions
    [help_url] => http://developers.box.com/docs/#errors
    [message] => Access denied - insufficient permission
)