In the folder there are two notebooks.

It is about DE wrt S and T for 2L-4P (internal masses=0, p^2=0 legs).

Run the Baikov-2L-4P-DE and you get the “tmpfile.m”.
It contains the DE for the 8 MI wrt to S and T based on different syzygies.

Then run the Fire-2L-4p-DE and you get the comparison with Baikov approach.

This is just to setup the DE. So FIRE is still used for reduction.

So you need FIRE and you need to download and install the MathematicaM2 package, version 0.98, by Yang Zhang (see https://bitbucket.org/yzhphy/mathematicam2).