Filip Höfer chess software supports games in the Portable Game Notation (PGN) format. Great games in the PGN format can be downloaded from many sites including:
The Week in Chess Magazine - new master games in PGN every week
A very large collection of master games and openings
Chess games database and community
Note that some of the downloads are zip files. To get PGNs out of a zip file, simply right-click the file and select Extract all.
The PGNs can be opened in Chess 2022, Chess 2020, or Chess 2013. Chess 2022 allows opening PGN (and FEN) files directly from Windows. All these apps support file opening via the menu bar: Go to the File menu and select Open...