How to link to files in Contao 3

So, in previous versions of contao, all I had to do was mark a work, add a link and then choose a file (e.g. a PDF) from the list (whatever I had previously uploaded). Now that option is gone. I can link to pages or URLs, but not files. What's the correct way to do this now?

In Contao 3.4 when you open the pagepicker in tinyMCE you can switch to the filepicker.
Read more here https://github.com/contao/core/issues/6974

You also can link manually to a file when you first get the UUID of a file from the file manager and then use {{file::UUID}} e.g. {{file::c67514ce-d9c8-11e3-8217-000c29e44aea}}

What about 3.3. It needs to be something an Editor can do.

If you followed the link I gave you, you'll find, that you can switch back to tinyMCE 3.