In the LGUP window, look for the File Path section. Click the three dots (...) and browse your PC to select the KDZ or TOT firmware file you downloaded. Choose the Process:
Supports full "Refurbish" (clean wipe) and "Upgrade" (data-preserving) modes for KDZ and DZ firmware files. Usage Guide lgup 1.17 patched
Using this tool requires a specific environment to ensure the phone is recognized correctly. In the LGUP window, look for the File Path section