Customisation for current source code

I have purchased source code for my taxi business, unfortunately that app doesn't have some features which I required, it's basically built with node is and react native Android taxi booking web+app, now I need experienced developer to implement some features.

About app : app is basically a taxi booking system with website admin panel. That doesn't have features of choice of trip option like outstation ride, city ride, rental packages so those options needed now with admin panel