The offline install instructions shown under Method 3 on https://dbatools.io/download/ instruct the user to use https://dbatools.io/in. This is a redirect to https://raw.githubusercontent.com/sqlcollaborative/dbatools/master/install.ps1, and that is a dead link.
This section of the Download page should instead direct users to Chrissy's blog post at https://blog.netnerds.net/2023/04/offline-install-of-dbatools-and-dbatools-library/, or the content of that post should be integrated into Method 3 on the current Download page.