slack.chat.command not working

[vikassinha2019]

Getting following response:

{"ok": true, "response": "Oops, that didn\u2019t work. Try again, maybe?"}

[ErikKalkoken]

Hey
what did you send?

[vikassinha2019]

I wanted to run slack slash commands via api. Though no native support was available, I ended up at this repo via stackoverflow link.
I ran the script as described, but it is not running and giving above mentioned response.