Apple closed the signatures of iOS 13.2.3
Apple has stopped signing iOS 13.2.3, preventing users to downgrade or restore to that firmware.
Currently, the latest firmware from Apple is iOS 13.3. Those who update or restore their iOS device, will be able to install only the latest version of the operating system. The developers are currently testing iOS 13.3.1 beta 1.
To those who are interested in the jailbreak we recommend that you do not typically update their device; however, the jailbreak checkra1n recently released makes it possible to jailbreak most devices, including iPhone 5s and iPhone X on any firmware version above the iOS 12.3. Checkra1n has already been updated with support for iOS 13.3.
For those who are interested in the jailbreak checkra1n, you can use our guide to perform the procedure correctly.