Visit shsh.host and enter your device's (found in 3uTools under the device information tab) to see if you have valid blobs saved on their servers. Import these blobs into 3uTools before starting the flash.
You are trying to install an iOS version that Apple has stopped "signing". Outdated Software: How To Fix Error Unable To Request Shsh On 3utools When
: Your firewall or a weak internet connection is blocking 3uTools from contacting Apple. Visit shsh
Remember: Always save SHSH blobs while iOS versions are still signed. Don’t wait until Apple closes the window—otherwise, 3uTools will forever show “Unable to request SHSH.” How To Fix Error Unable To Request Shsh On 3utools When
: This is the most common resolution. Download and install the latest version from the Official 3uTools Website to ensure compatibility with Apple's current servers. Check Signing Status