You already linked the answer to your question: https://www.mathworks.com/help/vision/ref/cameraparameters.html
If you get the camera parameters with the Camera Calibrator App from MATLAB you can save the parameters as object directly to workspace and from there to a .m-file.
If you have the parameters yourself, just build the camera parameter object with the syntax in the link:
cameraParams = cameraParameters(Name,Value)
where Name is is your properties and Value the value of the properties. For example:
cameraParams = cameraParameters('ImageSize',YourImageSize, 'RadialDistortion', YourRadialDistortion, 'TangentialDistortion', YourTangentialDistortion,...and so on).
There is already a example at the end of the link.
