He asked about JS closure, I explained through an example. he asked me to develop React problem using timer. basically two buttons; one to start and another one is stop like app . So I asked them to provide a coding platform and told that local react setup is time taking thing. if we want running React setup in local, why don't we put it as pre-interview instructions.? It's minimum thing that if we are asking someone to solve a problem, at-least they have to provide a platform to run the app