The view-once feature is activated for photographs and videos by selecting a photo or video to share and then pressing on the circular “1” symbol on the right side of the description box. There is presently a specific send button icon with an extra padlock for text messages, however, the design may change once the capability is released from beta.
Given that the functionality is now available in WhatsApp beta, it’s realistic to anticipate it to appear in a future release, but there are no assurances.
