I'm following (https://dev.office.com/sharepoint/docs/apis/webhooks/webhooks-reference-implementation) tutorial to integrate Sharepoint Online into our application.
The application is written using Asp.Core 2 with Sharepoint REST API because CSOM is not supported by the core.
The problem is that in the tutorial webhooks are created only for one site. How do I create webhooks for other sites in Sharepoint Online? How do I get a list of these sites using REST API?