The quickest / easiest way to add a new user does not require any email interaction. Just go to Administration > Users > Add a new user and fill in all the various fields, including the “Email verified ” and ” Approved by administrator” ones. Then contact your user by whatever means you normally contact them and tell them their login details, as that isn’t triggered by this manual process.
Alternatively (and ideally for security) get them to apply to register using the “New account” option under Login on the Home page. That way not even you know their password, which is as it should be.