- Go through ms-settings:developers and enable developer mode
- Download https://github.com/der3318/musicsheet-viewer/releases/download/v1.0.6.0/DerChien.cer
- Right click to install the certificate for Local Machine as Trusted Root Certification Authorities
- Visit ms-appinstaller:?source=https://github.com/der3318/musicsheet-viewer/releases/download/v1.0.6.0/PianoSheetViewer.msixbundle to install the app