PHtrans calculations

Dear all,
I want to study phonon transport using the PHTrans module. Right now I am using version 4.1-b3, but I am not getting any proper directions on how to start on this. Whatever I understood, are GULP and SISL necessary for the PHtrans calculations, but sisl is giving errors (I tried the sisl/examples/ex_03.py at main · zerothi/sisl · GitHub ,available but its showing errors on sisl calculations).
Can anyone help me on how to do phonon transport calculation like photo current vs photon energy (similar to IV characteristics for electrons)? Or are there any alternative ways in which we can study this? Any guidance and reference will be really helpful.

Thanks in advance