You need an IPA to install. Use Safari to download an IPA file (e.g., a retro game emulator or a modified YouTube client). Save it to the folder in iCloud Drive or your "Downloads" folder.
Mitigation: If your apps stop working, you will need to wait for the shortcut creator to update the workflow with a new certificate, or purchase a private developer certificate. Alternative iOS Sideloading Methods shortcut ipa installer
Ensure that options allowing advanced script execution or sharing are enabled (varies slightly by iOS version). Step 2: Download a Trusted IPA Installer Shortcut You need an IPA to install
Several community-developed shortcuts and comprehensive guides facilitate on-device IPA installation: Signed Installer shortcut ipa installer