Trigger when you join the community

What is the best trigger to use when a user joins Fluent Community to start the welcome automation? I already have a community and courses, so logging into Fluent Community means a new user in that community.

I was thinking of automatically adding to, say, “Say Hello” (via mapping) and then start the trigger: Joined in a Space. Because I understand that the user who joined is not automatically a member of any space.

Maybe there is a less complicated way?