To load KML files from Google Drive, you need to provide your own API Key and Client ID.
1. Go to the Google Cloud Console.
2. Create a new project or select an existing one.
3. Enable the 'Google Drive API' and 'Google Picker API'.
4. Go to 'Credentials', click '+ CREATE CREDENTIALS' and select 'API key'.
1. Go to the Google Cloud Console.
2. Go to 'Credentials', click '+ CREATE CREDENTIALS' and select 'OAuth client ID'.
3. Select 'Web application' as the application type.
4. Add 'http://localhost' and your deployment URL to the 'Authorized JavaScript origins'.