Update your WhatsApp to the latest version of 2.22.21.83 and then open your WhatsApp to check whether the create call link feature is available to you or not.
WhatsApp s new Call Links feature is now available to more users across the globe. It lets you invite anyone to a group call via a shareable call link. - SamMobile
Put it in View Once and you never have to worry about any copies made via WhatsApp for iPhones. Meta and WhatsApp are planning something new for their iOS version, and it is allegedly aiming to block screenshots on photos and videos that were sent via the "View Once" feature.