Hello,
You can right click on PNG file, select Open with > Photos.
Note that Photos app came pre-installed with Windows 10. If you still can't find Photos app on your system, install it from Microsoft Store.
You can set Photos app as default app for .png files:
https://support.microsoft.com/en-in/help/4028161/windows-10-change-default-programs
You can also enable Windows Photo Viewer, if you like, using this guide:
https://www.kapilarya.com/open-images-with-windows-photo-viewer-in-windows-10
Hope this helps!
Note: Included link in this reply refers to blog post by a trusted Microsoft MVP.