A S3 bucket is an online file storage service.
You can configure your outgoing webhook:

Click on the Add button to add an outgoing webhook.
The webhook add page opens:

S3 as providerThe default archiving service can be invoked via the keyboard shortcut shift+s when viewing an article.
Once configured, you will see a new entry in the context menu of the article.
You can now send an article to a S3 bucket.