How can by the desktop edition

hi I am looking to by desktop edition for add user name and password can you help me
thank you

Desktop version is free version. It does not have paid version.
You should buy cloud version or server version which supports multiple users.

Since the desktop edition is single-user, security is presumed to be controlled by the owner of the machine it is installed on. If you need to control access to the program, create a new user account for your computer and install the program for that user only.

thank you
i receive 3 time a day a massage of "475 day of expire"
and also i don’t have server and not internet all the time
and i need to add user name and password for sales counter
thank you again

It sounds like you are running the server edition on your desktop. If that is true, you downloaded the wrong program. Back up you data according to this Guide: https://www.manager.io/guides/8890. Download the correct desktop edition from here: https://www.manager.io/desktop/download/. Launch the program and add your business from the backup file as described in the first Guide.

You will not be able to add user names and passwords.