To access the YouTube data API, you will first need some kind of google account.
The API has two methods of authentication, OAuth2 and API keys. This application uses API keys.
These API keys are basically like passwords, and so once obtained, they should not be shared.
The instructions for obtaining an API key are copied below from [here](https://developers.google.com/youtube/registering_an_application):
1. Open the [Credentials page](https://console.developers.google.com/apis/credentials) in the API Console.
2. Create an API key in the Console by clicking **Create credentials > API key**. You can restrict the key before using it in production by clicking **Restrict key** and selecting one of the **Restrictions**.
To keep your API keys secure, follow the [best practices for securely using API keys](https://cloud.google.com/docs/authentication/api-keys).