It just has to be a "Job" you get paid to do. People will absolutely sign up.

The problem is that there will be far too many people wanting that job, so you have to filter somehow, and that's basically eugenics which isn't the most fun, so I guess you'd have to have a lottery and deal with the fact that like 10% of the population will constantly riot about someone who "doesn't deserve it" getting paid to raise kids.