Developing "classful" applications using javascript on nodejs

I'm working on an advanced SaaS application that relies heavily on classes and the relating logic.

I've tried to "map" entities to objects as it should be done , but that's not resolving the issue for my case as a lot of problems when trying to implement the design patterns related to OOP.

Besides , there is some ambiguities on how to use properly "class" in nodejs (should I export the class in order to instanciate it somewhere else or what?). Help appreciated , even with suggestions.