How can I upload a file with no extension

I am trying to upload a configuration file so I can include a link to it in my post. And I get a Security error, because the file type is not allowed.

My config file has no extension.

I found this question: Adding file types in wordpress

Is there a way that I can add the mime type of ” for a “No Extension” type?

Why not just add .txt to the file? It’s probably the safest thing to do. If you need the file name to display without the extension, you can always filter the string.