Exporting .png files

I’ve got some PNG files I want to export from a project’s research folder. They’re the “raw” files, not inserted into text files.

When I select multiple files in the binder, and then go to File->Export->Files, I can’t figure out what to do to enable the Export button. Selecting a single file lets me do what I want, but that’s kind of tedious.

Is there a way to export multiple non-text files from my research folder in one go?

The only thing you should have to do is supply a folder name at the top of the dialogue box, where the exported files will be collected.