First things first. Let's install the Redis DB on your machine and provision it in the Heroku environment.
The first step is to set up a Redis instance. You can provision it in your Heroku account. If you are working with this course offline, you might want to install Redis on your machine.
If you're using a Windows machine, use Windows Subsystem for Linux (WSL) and a package manager to install Redis:
sudo apt-get update
sudo apt-get upgrade
sudo apt-get install redis-server
On macOS, you can use the Homebrew package manager:
brew install redis