ModuleNotFoundError: No module named 'ethereum'

Hi, thanks for the good work done. I am trying to run cert-issuer using Ethereum but I have the error No module named ‘ethereum’ as could be seen below. Also included is my conf.ini file. I have already read other posts like https://community.blockcerts.org/t/no-module-named-cert-issuer/293/8 but still does not work for me.

. By the way I’ve already run the command
“python setup.py experimental --blockchain=ethereum” and was successful as could be seen below. . Meanwhile, when I run using “python cert-issuer -c conf.ini”, I get the error "python: can’t open file ‘cert-issuer’ ". Any help, please?