FID score for MNIST pytorch

Hi all!
Hope you are having a great day. Thanking in advance for your valuable time.

Has anyone tried calculating FID score for MNIST dataset(i.e grayscale images) using DCGANs pytorch?

I have this project here which calculates FID for MNIST, but it is difficult to understand and debug.

Another question is do we need to store images and then calculate FID? or there is another way around?

Many Thanks