If you read a bit further, there's a jailbroken variant that has Sileo and Trollstore installed, so you can run whatever IPAs

Where?

Edit: ah now I see, in the main readme under heading Firmware Variants. https://github.com/Lakr233/vphone-cli#firmware-variants

Exactly. It means it cannot download apps from the App Store or use Apple services and Apple knows this deliberate limitation.