Open QCAD. Go to Edit > Application Preferences > File Handling > DWG Import . If the plugin is active, you will see a tab labeled with configurable version settings (e.g., "Save as DWG 2018").
When equipped with the professional plugin, QCAD offers command-line tools (like dwg2dwg or dwg2pdf ) that allow you to convert hundreds of files at once without opening the GUI. How to Install and Activate the Plugin qcad dwg plugin