How to change dynamic(aerodynamic) model in SIH mode

Hello everyone,
I m currently working on SIH mode of fixed wing to test my own dynamic model plane. Cuz my plane’s mass, inertia, aerodynamic parameters are all different compared to original SIH plane model.
As mentionned on this website,
it shows that , " The whole simulation remains inside the PX4 environment. Developers who are familiar with PX4 can more easily incorporate their own mathematical model into the simulator. They can, for instance, modify the aerodynamic model, or noise level of the sensors, or even add a sensor to be simulated."
But I can’t find anywhere to change dynamic model of plane in SIH mode.
Anyone have solutions for this ?