download the script
wget https://gist.github.com/code-R/f1465e166c47a676bcab110d29624197
download the audio file
and then run the script you have downloaded
pip3 install google-cloud-speech==0.36.0 (if you dont have pip3 try pip install google-cloud-speech==0.36.0)
python speech_to_text.py
this will give you instructions on how to setup service_account/project and enable speech api on the service account
https://cloud.google.com/docs/authentication/getting-started