Unable to install NixOS on Raspberry Pi using tutorial

[misogihagi]

I tried to install NixOS on my Raspberry Pi by following this tutorial:
https://nix.dev/tutorials/nixos/installing-nixos-on-a-raspberry-pi.html

However, I encountered the following issues:

1. The command to download the SD card image fails with a 500 error:

wget https://hydra.nixos.org/build/226381178/download/1/nixos-sd-image-23.11pre500597.0fbe93c5a7c-aarch64-linux.img.zst
# Returns: 500 Internal Server Error

2. Even if I manually download the image and continue,

 curl -LO https://hydra.nixos.org/build/325041790/download/1/nixos-image-sd-card-26.05pre969196.46db2e09e1d3-aarch64-linux.img.zst

I get the following error:

Unable to read partition as FAT error

like this

Could you please provide the latest and correct procedure for installing NixOS on the latest Raspberry Pi? Any updated instructions or recommendations would be greatly appreciated.