Running ngspice for sky130 process and open_pdks

[emfhasan]

I am trying to use the ngspice simulator with xschem using skywater130 process and open_pdk. I got the following error when I was running one test example:
Error: Could not find include file ~/home/eda_work/eman/hassan/skywater-pdk/libraries/sky130_fd_pr_ngspice/latest/corners/tt.spice

I followed the instruction in the following video for Stefan Schippers to install the open_pdk, xschem for sky130 process and ngspice: https://www.youtube.com/watch?v=jXmmxO8WG8s

Any advice in this regard?