The app and the licence are separate. Download and run the software for nothing — the licence key is what removes the trial watermark from your reports.
Get it from the Microsoft Store. It installs as a proper Windows app, updates itself, and Windows raises no security warning.
Currently listed under its former name, P6 Baseline Schedule Sentinel — the Store listing is renamed with the next release.
Do this whenever you're ready — during the trial or after it ends. You receive a key, which you paste into the app to unlock clean, unwatermarked reports.
Opens the checkout page. A direct .exe download is available there
too, if you would rather not use the Store.