Use it like this:

• For iSH: (make sure you are in a WiFi network with UPnP enabled)

$ ./AltServerUPnP -u "[YourDeviceUDIDHere]" -i "[YourDeviceIPInNetwork]" -P "[YourJitterbugPairFile.mobiledevicepairing]" -a "[YourAppleID]" -p "[YourAppleIDPassword]" [IPA to install]

• For normal Linux host:

$ ./AltServer -u "[YourDeviceUDIDHere]" -P "[YourJitterbugPairFile.mobiledevicepairing]" -a "[YourAppleID]" -p "[YourAppleIDPassword]" [IPA to install]