Currently I use the “root” user to connect from WHMCS and create Virtualmin Accounts
I would like to create a new user in Virtualmin/Webmin that WHMCS could use to connect instead of root (so root PW does not need to be stored on WHMCS)
How would I create such an user?
What exact settings does this user need?
I do not use WHMCS however in theory you could create a new user (in linux or webmin) that will have root privileges and use that account instead.
What are you trying to gain however here? Better security in WHMCS? Someone that has the new account you created will have the same powers as if he was using the root account.
I think WHCMS is using the Virtualmin API for account provision - so it just sends the commands to Virtualmin. I thought that for this task another user (not with root privileges) can be used. Virtualmin itself will still run the tasks as root - but the connection from WHCMS to Virtualmin would not need the root user, and so WHCMS would also not have to store the root user PW.
Note that you can create a user with sudo privileges for running commands as the root user. Virtualmin will treat any user listed in the sudoers file as a Master Admin (if they have the ability to run all commands with sudo that is).