You can follow this guidebook to make your google-ads.yaml file. And for the sample role you provided, below are the definitions of each but you can check this sample template for more details about it.
Developer token
A developer token is required when making requests to the Google Ads API regardless of whether you're using the OAuth2 or Service Account configurations. To obtain a developer token see: https://developers.google.com/google-ads/api/docs/first-call/dev-token
developer_token: INSERT_DEVELOPER_TOKEN_HERE
OAuth2 configuration
The below configuration parameters are used to authenticate using the recommended OAuth2 flow. For more information on authenticating with OAuth2 see:
https://developers.google.com/google-ads/api/docs/oauth/overview
client_id: INSERT_OAUTH2_CLIENT_ID_HERE
client_secret: INSERT_OAUTH2_CLIENT_SECRET_HERE
refresh_token: INSERT_REFRESH_TOKEN_HERE
Login customer ID configuration
Required for manager accounts only: Specify the login customer ID used to authenticate API calls. This will be the customer ID of the authenticated manager account. It should be set without dashes, for example: 1234567890 instead of 123-456-7890. You can also specify this later in code if your application uses multiple manager account + OAuth pairs.
login_customer_id: INSERT_LOGIN_CUSTOMER_ID_HERE