Thanks for pointing out. I just didn’t know how to execute those scripts. Although, I’m not good at getting hints but this helped me in getting things straight.
I edited the “containers/app.yml”
cd /var/discourse/containers
sudo nano app.yml
And added the template path for mysql-dep template: - "templates/import/mysql-dep.template.yml" as shown below
After that, just rebuilt the app and all dependencies required for flarum_import.rb were installed.
Worked like a charm!