https://en.wikipedia.org/wiki/Door-in-the-face_technique

Right to Work means you can have a union job but not join the union. You have the right to”right to work” without being a union member or paying any union dues. Generally it means you get all the benefits without contributing but also unions are usually a lot weaker since so many people opt out, so also the benefits are lesser. Because it is governed by state-level laws, details vary from state to state.