Saving
You can export the currently selected stream using Station ▸ Save or by pressing F2. A file dialog opens, where you can adapt the title.
The extension of the filename decides on the saved link format. Per default a .m3u file is created, because that's what most audio players understand.
You can also save in .pls or .xspf or .asx or .smil format. In current releases the file extension is automatically adapted when changing the filter dropdown (bottom right corner in the file dialog).