Error trying to extract Dell BIOS using dreamwhite's script

Hi, I am trying to install macOS 11 on my Dell OptiPlex 5060. Followed the Dortiana guide completely until I figured out I need to fix the CFG lock. When trying to extract the BIOS from Dell's website using the recommended script, I am getting following error:

https://preview.redd.it/b4x5tleaf3ac1.png?width=1242&format=png&auto=webp&s=d303577ddd6000fd27c8b854085d858e73996a4a