coz any1 can go in and see our transactions its should have privacy. confidential info
Hm, you possibly using the desktop version.
username/password available only in server and cloud version. If you happy with desktop version and still want to protect it, have username/password for your computer and have auto lock at system idle time.
Like ismail mentioned, you are able to lock your computer in order to prevent access to Manager.
If you allow other employees to access the computer, and they have no reason to use Manager, then I would suggest you either move Manager to a different computer that only you have access to - or sign up for the paid Cloud Edition (Cloud Edition | Manager) and import your data (Manager Cloud).
You could also create a different, password-protected user account on the computer and install Manager for that account. The point is that you cannot protect the desktop edition of Manager, you must protect the computer or the user account on the computer. This is the consequence of using a free edition of the program.