Where do incomplete software updates are stored on a Mac?

I've been trying to download a copy of Big Sur from App Store (still it was taking me to download it from System Preferences app) to make an installation flash drive for another Mac with replaced SSD.

I downloaded half of the bundle, then the download interrupted. However, the disk space remains taken. I need to know where the incomplete part of the download is stored, so I can delete it and clear disk space.

I googled a lot of forums, some people say that it stores in Applications folder, which is not true, some say it stores in /Library/Updates, but there's only .plist files for the update there, some say it stores in /Library/Application Support, which is also not true, I studied every folder inside and haven't found anything.

I need help to know where do Macs (macOS 11.x) store incomplete system and application updates.