According to your documention, you have Confluence webhooks, but apparently that feature was pulled from Confluence some years ago.

At the moment, you only support webhooks for JIRA.

To be able to integrate Confluence with other tools we need Webhooks. https://en.wikipedia.org/wiki/Webhook 

Webhooks are the defacto standard today and many tools (chat, ticket systems, bugtrackers, runners, CI, etc. pp) support them.

You already have listed all the Webhook events that are needed for Confluence on your outdated documention (URL: https://developer.atlassian.com/static/connect/docs/latest/modules/common/webhook.html)

Confluence Webhook events

• attachment_created
• attachment_removed
• attachment_restored
• attachment_trashed
• attachment_updated
• attachment_viewed
• blog_created
• blog_removed
• blog_restored
• blog_trashed
• blog_updated
• blog_viewed
• blueprint_page_created
• comment_created
• comment_removed
• comment_updated
• connect_addon_disabled
• connect_addon_enabled
• content_created
• content_restored
• content_trashed
• content_updated
• content_permissions_updated
• group_created
• group_removed
• label_added
• label_created
• label_deleted
• label_removed
• login
• login_failed
• logout
• page_children_reordered
• page_created
• page_moved
• page_removed
• page_restored
• page_trashed
• page_updated
• page_viewed
• relation_created
• relation_deleted
• search_performed
• space_created
• space_logo_updated
• space_permissions_updated
• space_removed
• space_updated
• theme_enabled
• user_created
• user_deactivated
• user_followed
• user_reactivated
• user_removed

In addition an admin page is needed, where webhooks can be created.