AltServer is an IPA signing platform for Windows and macOS allowing users to sideload the AltStore app on supported iOS devices. This program is the only working alternative for Cydia Impactor that is compatible with the latest version of iOS 13.5. Sideload almost any IPA package for free using this software.
Free development certificate allows you to install up to 3 apps per device and sign no more than 10 ID's. Every 7 days after signing, you will have to connect your iPhone to your PC and repeat the install process. AltServer will sign IPA packages and send them back to AltStore for installation on the device.