It's also possible to download the accounts.json file and transfer it into the directory. By the looks of it on MacOS the directory is $HOME/Library/Application Support/PrismLauncher/.
Edit: If you are using the portable Windows version you can place the accounts.json file in the root directory of the install.
I have tried many times to use it and it didn't work either on windows or on linux, indeed the one I have on github changed 2 times from the one you currently are commenting
It doesn't, it's Foss. To play Minecraft though you still need to buy the game, this script makes the launcher think you have bought the game even if you haven't.
Prism launcher is just an open source replacement for minecraft’s official launcher. But you still need to have bought the game and be logged into your microsoft account through prism launcher to be able to install the game and play online. This script bypasses those systems of the launcher.