We don’t host the LG K3 LS450 stock ROM at the moment due to having to reduce our server expenses.

If you would still like the LG K3 LS450 firmware, you can check one of our competitor sites in Google Search. Otherwise, you can search for LG free firmware update tools on GitHub or XDA Developers. Lastly, you can try asking LG for the firmware file, and they may let you download it directly from them, though smartphone manufacturer’s typically preferred you send in your device to them.