CFX - how to define custom scalr transport equatio

CFD user

Hello All]

I am trying to solve a custom scalar transport equation in CFX but I am confused about the controls and the way to set the transport equation terms like diffusive, advective etc

I am able to define additional variables (scalar) and set their units. But I dont know how to go from there to set the terms of the governing equation and then set the boundary conditions in CFX-Pre. I have recently moved from Fluent to CFX and quite unfamiliar with the interface. I am not able to find any tutorials in this regard. Any help pointing to the right direction will be greatly appreciated

Regards CFD User