Occasionally, a new blog owner will want to make a blog part of his website. Long ago, before custom domain publishing became a Blogger option, it was normal to publish a blog into a website subfolder. FTP Publishing let anybody publish a blog as "www.mywebsite.com/blog". But FTP Publishing ended, shortly after custom domain publishing replaced it. And now, publishing to a subfolder is not an option.
What Blogger won't tell you