The iMac 24-inch (M1, Four Ports, 2021) comes with a firmware identifier iMac21,2. It has a Board Configuration of J457AP and a Board Platform of t8103. The CPID and BDID are 33027 and 42 respectively.
IPSWDL.COM is a website that provides download links for IPSW files, which are used to install or restore firmware on Apple devices. These files are sourced directly from Apple's servers.