Did you see the blue console box appear when it booted? Did it load the ISO from the USB drive as a virtual DVD?
This usually indicates that Win10 Setup (WinPE) cannot access the USB drive because it does not have the correct USB drivers for your (new?) system. Try unplugging and re-connecting the USB drive into a USB 2 port or use a USB 2 extension cable.
Alternatively, use a later version of the ISO which may include the required USB 3 drivers for your system - OR - boot to a Windows 10 Retail 2019 Install ISO, run WinNTSetup.exe and install the LTSC ISO using that. https://www.easy2boot.com/add-payload-files/windows-install-isos/winntsetup/
Output from ProduKey after installation shows:
Product Name : Windows 10 Enterprise LTSC 2019 Evaluation
Product ID : 00425-10000-00000-AA840
Product Key : N7HMH-MK36Q-M4X93-76KQ2-6JHWR
By Steve Si
Subject Re: Re: Re: install error