mt_prep_gamma_snap starts to identify the pixels which are candidates for persistent scatterers based on your amplitude dispersion threshold. You simply navigate to the INSAR_master_date folder and type it in.
https://homepages.see.leeds.ac.uk/~earahoo/stamps/StaMPS_Manual_v3.1.pdf (Chapter 6)
To be honest, I didn’t get it to work under cygwin because there are many syntax differences which might cause problems. Please have a look at our overview topic: About the STaMPS category and go through the discussions on the problem. There were some who managed to do it.