I am getting
-bash: airflow: command not found
after installing Apache Airflow. I am using Google Cloud Compute Engine and OS is Deb
If installed with sudo, as mentioned by Sirajus, it will be placed in /usr/local/bin/.
Without sudo, it will be placed in the ~/.local/bin/ folder. This folder will not be added to the PATH environment variable automatically.
So you can either add it to the PATH environment variable or install it using sudo.