For further help, you can check official guides on the 3uTools Tutorial Page .
Use an original Apple lightning/USB-C cable. Try a different USB port on your computer, preferably one directly on the motherboard (back of the PC). i unable to request shsh 3utools fix install
Apple only allows you to install "signed" versions of iOS. If you are trying to downgrade to an older, unsigned version, 3uTools will always fail the SHSH request. For further help, you can check official guides
Paste the ECID into the host site to see if valid blobs exist for the firmware version you want to install. if you have them saved? How to Fix 3uTools 9% ERROR Unable to request SHSH Latest For further help