I know how to do it. I suck at doing it on my own forums.
If you onboard correctly, you have a better chance of converting lurkers into active contributors. However, onboarding takes some work. You have to be willing to put in some time developing a relationship with each member on your forum.
But it all pays off in the end if you're trying to build a community.
I'd like to average 5+ members online before 2027. I want more members to regularly be online, that's one of the biggest obstacles for my forum is taking it to the next level.