Question about ASUS Rog Zephyrus G16

Hello everyone, how can I get an additional 240W power supply for the 4090 version, which does not have a round plug? I had a back and forth with Asus and was at least able to find out an article number (0A001-00971100), but this cannot be ordered from Asus. I was referred to a company in Germany, but they can't get the power supply. It's quite annoying, as you can't even order the power supply as an accessory or spare part for a laptop in this price range. Are there any other options?