How do I pass a value from a program to a variable in.usf?

[waterswaterAhHa]

I am learning the shader pipeline, I cannot explain it well, but you can see the official file “PostProcessTestImage.h” and “PostProcessTestImage.cpp”, and based on the “PostProcessTestImage.usf” you can find something like XXXPS::FParameters* PassParameters contain the shader parameters passed from C++