It is a feature that you seem to have known. Yes, it is direct video calls, which are sure to start from today with access to the users of the application, where the call to the other party can be made simply by pressing the video icon that will appear at the top of the chat window next to the voice dialing icon,
The service will be launched gradually today, as it will be activated first for users in Belgium, Canada, Croatia, Denmark, France, Greece, Ireland, Laos, Lithuania, Mexico, Nigeria, Norway, Oman, Poland, Portugal, the United Kingdom, the United States and Uruguay. The service will gradually reach the rest of the countries in the coming months.
As for the way to activate it, there is no practical way, so just wait for the software or application update to reach your phone automatically.