How to Futurerestore to iOS 15.1(.1) on Ubuntu

1. Install git
sudo apt-get update && sudo apt-get upgrade && sudo apt-get install git

2. Install Library-iPhone
git clone https://github.com/elrhk/Library-iPhone && cd Library-iPhone && chmod +x autobuild.sh && ./autobuild.sh

3. Change directory
cd ..

4. Remove Library-iPhone
rm -fr Library-iPhone

5. futurerestore command (Stops in recovery mode by Linux)
./futurerestore -t <.shsh2 file> -d -c 15.3.1 <15.1.x ipsw file> --latest-sep --latest-baseband

6. Run in recovery mode (Not required for Mac)
sudo ./futurerestore -t <.shsh2 file> -d -c 15.3.1 <15.1.x ipsw file> --latest-sep --latest-baseband

Note: Change "--latest-baseband" to "--no-baseband" for iPod touch and Wi-Fi model iPad.