I’ll let you compare the nix 2.4 manual page (https://web.archive.org/web/20211201073051/https://nixos.org/manual/nix/stable/command-ref/new-cli/nix3-flake.html) with the current one (https://nixos.org/manual/nix/stable/command-ref/new-cli/nix3-flake.html).
https://gist.github.com/yunfachi/6c073cc6edc18f78cfc60bb9bb3f7143