Need to know access required to attach webhook in SharePoint sites library

@abhay kumar

Thank you for using Q&A Platform

I understand You are trying to attach a webhook to a SharePoint site library using Sites.Selected permissions with read-write access, and you are getting error while attaching webhook and some library and not able to find site pages which is page library.

Webhooks are only supported for SharePoint list items, which includes document libraries but not site pages libraries. some libraries may not support all event types, especially custom or system libraries like Site Pages.

Use Graph Explorer or SharePoint REST API to list libraries in the site. Confirm if the Site Pages library is returned and accessible.

Ensure your app registration has Sites.Selected permissions and that the Site Pages library is explicitly granted access.

If webhooks are not viable for Site Pages, consider using Power Automate with polling or event-based triggers as a workaround.

For testing, try granting full site access to confirm whether the issue is permission-related or a platform limitation.

I hope this helps in resolving the issue, do let me know if you have any further questions on this