There are 3 levels of user permissions within Approvals for viewing reports and configuration - Owner, Admin and User. User permissions does not affect interaction options between Approvals and a user within Slack.
Full permissions - This is set at a user level via the people tab
Full permissions - This is set at a group level via the groups tab. If a user is removed from a admin group they lose permissions.
Can only view access reports for their own approval and access requests