Original image by William Warby. https://www.flickr.com/photos/wwarby/16414155179/in/photostream/
Sites in SharePoint are created all the time, not only for SharePoint, but also as storage for Yammer, Teams, Planner and other services in Microsoft 365. There are ways to keep track of them, but the ability to automatically detect a new site creation is quite appealing. Automatic detection means a trigger of a Power Automate (Flow) or a Logic App.
There are a few blog posts that exactly describe how you can detect when a new site is created in SharePoint Online: