Define Gaussian point spread function

I want to define a point spread function as a Gaussian. I know the amplitude, sigma and mu for the Gaussian. How do I generate a PSF from those parameters? I would then like to use the PSF in the Lucy-Richardson deblurring algorithm.

I am thinking to define: PSF = imgaussfilt(Image, sigma), but this only allows me to define sigma.

Is there a MATLAB function that allows me to define the amplitude, sigma and mu for the Gaussian function?

Thank you.