If the displays still do not work, please review these points:
After installing, ensure you have completed Steps 4.4 to 4.9 in the linked article, which includes running the application after installation and selecting “Launch automatically after logging-in”. This will ensure it starts automatically every time you log-in.
On Apple M1-based Macs, you may be prompted to install Rosetta during the DisplayLink install process. This is currently required to allow DisplayLink to work on Apple Silicon Macs.