WhatsApp added guest calling today. Anyone with a WhatsApp account can create a call link and send it to someone who has never installed the app, and that person can join the voice or video call from a computer browser.
To set one up, open the Calls tab, tap "+", and share the link that WhatsApp generates. Guests land in a waiting room until the host lets them in. Once inside, they can share their screen, raise a hand, and react with a thumbs up or a heart, but they can't see anyone's phone number, send messages, or add other people. Hosts can boot a guest at any point. WhatsApp says the calls stay end-to-end encrypted, have no time limit, and hold up to 32 people.
This is basically the FaceTime link trick Apple added back in iOS 15, and it makes WhatsApp a lot more usable for the one person in every group chat who refuses to sign up. WhatsApp also says a calendar plugin for creating calls from Google Calendar and Outlook is coming later this year.
— via MacRumors