I am part of a development team working on a charger load system project. Our responsibilities include developing the front-end and API management components. Currently, we are in need of guidance regarding the implementation of an OCPP (Open Charge Point Protocol) server. We will need something that can update the charge rate of the charger and the charger to send through its state and state of charge. It requires to be on OCPP 1.6J. Can any recommend a library that would get us started with?