When you create your first vacation request, @attendancebot will ask you to state the username of your manager. Please note the username is '@' followed by the username you use to chat with your manager on Teams. You can also change your manager anytime via 'change manager'.
Once set, your subsequent vacation requests will go to your manager for approvals.
Only vacation and travel types go for approvals. For the rest of the vacation types, only an FYI message is sent to the managers.