How to integrate "C" code in S - Function builder

Hello, I have working C code, I want to use that C code inside the S function builder. So, I need to know the procedure to Integrate the C code inside S function builder.

[Amish]

The following documentation should give you a fair idea on how to implement a Basic C MEX S-Function: https://www.mathworks.com/help/simulink/sfg/example-of-a-basic-c-mex-s-function.html