I recall that there was a way to mass-invite people to the site by copying and pasting a CSV.
I want to do the same thing for groups, but instead I have to manually enter one username at a time.
My use case is that I’m trying to separate our discourse members into patients & researchers. On our main site, we track which members are researchers, and they use SSO to log onto discourse. Thus it would be very straighttforward for us to do a nightly copy-and-paste of usernames that should be placed in the Researchers group.
Yes, there is a howto here on sending batch invites… just follow that. If the email already exists on the site, they will just be granted whatever new group membership that invite specifies.