Before you can use the Gist REST APIs, you will need to have a valid getGist API key. Below are the steps you will need to create a Gist API key.
Open a browser tab and Log In to your Gist Account (getgist.com). Click on “Settings” on the top menu. Under the “API & Integrations” section on the left menu, click on “API Key”. Click on “Copy” to copy your API Key.
Shortcut link for getting an API Key: https://app.getgist.com/projects/_/settings/api-key