Hi Dr.,
I am Aster, an Independent Advisor and I'm here to help you with your problem.
Seems like you have to install Bash first. Try instaling Git Windows here: https://git-scm.com/download/win
Then you install Bash from there. You may refer to the steps in the link below on how to do it:
https://www.stanleyulili.com/git/how-to-install...
Then try running your script in the Git Bash terminal again with the bash command to see if it works.
Let me know if it helps, thank you.