Osmotic permeability "Pf" for water transport

GROMACS version: 2018
GROMACS modification: Yes/No
GROMACS version: 2021.6
GROMACS modification: No

I want to calculate the osmotic permeability (Pf) of water transport for my aquaporin membrane system. How I can do it using this using gmx-msd or is their any other method to do the same . I would appreciate if anyone could help me.

Best regards.