Administratively add (register) users to phpBB forum?

My website is primarily collections (albums) of bird photographs taken on and reports written about birding trips by a particular group of people.
About 60 people have chosen to get emails from me when I add a new set of photographs or trip report to the website.

I have now installed a forum where folks will be able to add comments, or ask questions about getting around on and using the website.
(They are mostly older seniors some of them up to 90 years old; and most have very little experience using computers and the internet).

I would like to pre-register for the forum, those folks who are on my recipient list so they will not have to go through a registration process to post to my forum(s). Is there some way for me to do that?

Even if I have to add them one at a time, I would be willing to do that, since that would be a one-time thing.