Requires the right to Write, see Admin groups.

Standard upload

1. Click on a folder.
2. Click on Upload.
3. Select files.
4. Click on Close or Edit/manage uploaded files.

Via drag-and-drop

1. Click on a folder.
2. Open the folder with the files on your computer.
3. Drag-and-drop the files to the file list in the project.
4. Click on Close or Edit/manage uploaded files.