For now, the feature is only available in one-on-one mode. In the future it will be extended to voice calls and group video calls
Desktop calls are designed to work on both portrait and landscape orientation. The call screen will appear in a separate, resizable window that will always be at the top of your computer screen, so you do not have to search it in browser tabs or other open windows. WhatsApp has confirmed that this functionality will be extended to voice calls and group video calls in the future.
How To Enable Calls And Video Calls On WhatsApp Desktop – First, you need to have the app installed on your computer to make free voice and video calls with your contacts on the WhatsApp desktop. Calls are available with the WhatsApp desktop: Windows 10 64-bit version 1903 and later and MacOS 10.13 and later.
All you have to do is make and receive calls and video calls on the WhatsApp desktop: have a microphone; A webcam; An active Internet connection on your computer and phone; Allow WhatsApp to access the computer’s microphone and camera.