There is no ebook to download at this link from the guide: https://aka.ms/finops/ebook

It is just an overview page with several examples and success stories for Microsoft in general. I guess the actual FinOps ebook should be here: https://azure.microsoft.com/de-de/solutions/finops

https://github.com/microsoft/finops-toolkit/blob/2367310bd84c71c7f7e22423655f00d120626cf6/docs/guide.md?plain=1#L41C34-L41C61