nix.registry.<name>.from

The flake reference to be rewritten.

The format of flake references is described in nix3-flake(1).

Type
attribute set of (string or signed integer or boolean or absolute path or package)
Example
{
  id = "nixpkgs";
  type = "indirect";
}
Declared
<nixpkgs/nixos/modules/config/nix-flakes.nix>