The Power Editor is a premium feature and (as of May 2020) requires the Business Plan to use. Some schools may have access at a lower plan level if you have been 'grandfathered' with that feature.
In addition, if you create pages using the V2 editor, you will not be able to use the templates in the Power Editor. They are only for V1 pages. Deployment of V2 templates are rumoured to be scheduled for Q3 or Q4 2020.
This is what you've all been waiting for! The glorious Power Editor. It's where all the magic can happen and all the disasters too.
First off, I've said it before but it's worth mentioning again - There is nothing here that you can break - nothing that can't be returned to default and the practices you've started (editing your code in an external editor) will mean you're mitigating any breakdowns before they even happen. In saying that however, accidents do happen - bugs in codes are inevitable so don't panic if something doesn't work the way you expect.
To access the Power Editor for your school, follow these steps:
The Power Editor page has three sections.