There is no direct trigger in PowerAutomate that triggers when a folder is created. You can achieve this with when an item is created trigger.
A trigger is the thing (event) that happens that starts the process. That’s what you’re asking the workflow to look out for. For example, when someone loads a file in a specific location.
Actions are the things you want the workflow to do once the trigger takes place. For example: Send boss email to approve new document.
You can create a PowerAutomate and have “When an item is created” as the trigger. The next you need to do is add a condition to check whether the item that was created is a folder or not.
You can put a condition and add “isFolder” equals to true in the condition. Rest of the actions you can keep inside the Yes of the condition.