Sudoers file error

SYSTEM INFORMATION
OS type and version Ubuntu Linux 22.04.4
Webmin version 2.105
Virtualmin version 7.9.0
Related packages SUGGESTED

How to fix this issue please help

man sudo
This will help you understand permissions.
man visudo
This will help you to make the appropriate edits.
This seems like a reasonable page too:

Of course you must do these changes as root or as someone with the proper permissions to edit the file, such as root.

And why are you trying this operation from a non privileged
account?

Basically I’m installing file manager: “GitHub - filebrowser/filebrowser: 📂 Web File Browser” for one of my domain. Does it cause any issue in virtualmin?

What you’re doing with sudo is irrelevant to how you use and configure sudo.

Virtualmin has a File Manager built-in. I don’t know if the one you’re trying to install would cause any trouble…but, I think I would be extremely cautious about anything that needs elevated privileges to install, especially a web app.

It’s not my decision it for one of my client server who want file manager like that, I think I should abort this task as it seems like security and server risk

Bottom line, if the user can’t install it in their virtual server space without sudo, then yes, it is a problem.

I think ‘jail’ might work but that’s another can of worms that you need to fully understand how to set up. I believe that gives them a full, self contained file system. But, that’s just from reading and comments, I’ve never done it.

EDIT: As @joe mentioned, there is a built in file manager. I haven’t set up permissions for a while and my server is personal so not an issue, but just check to make sure they have access to the built in solution.