Hello Tien Pham,
Please read more information about why-password-only-on-sign-in https://www.axcrypt.net/support/faq/#why-password-only-on-sign-in
If someone knows your system or Pc password, so you can sign out the AxCrypt app manually. After that nobody to decrypt the encrypted file without file password.
For example. If you sign in the Gmail account in your/common system. After that you work completed you have to sign out your gmail account in the system. same as you will complete your work you need to sign-out the AxCrypt app manually. AxCrypt app is designed like that only.