X is tinkering with video and audio calling at the platform formerly known as Twitter, according to a post Wednesday by owner Elon Musk.

“Early version of video and audio calling on X,” Musk wrote in a post that contained a screen capture showing how to turn the feature on in the platform’s settings.

The screen capture showed options of enabling voice and audio calls to those in a user’s address book, all verified users, and to people they “follow” at the service.

However, multiple users responded to Musk’s post saying they did not see the feature in their app, which was also not visible in a version tested by AFP.

The tycoon announced in August that voice and video calls were in the works at X in what was seen as a step towards turning the former Twitter into an “everything app.”

The calling features would work on iOS, Android, Mac and PC systems, and no phone number would be needed, he said at the time.

“X is the effective global address book,” the billionaire added.

Musk in July rebranded Twitter as X, saying it would become an “everything app” inspired by China’s WeChat that would allow users to socialize as well as handle their finances.

Since Musk bought Twitter last October, the platform’s advertising business has collapsed as marketers soured on his management style and mass firings that gutted content moderation.

In response, the tycoon has moved towards building a subscriber base and pay model in a search for new revenue.

Audio and video calls are expected to be among features offered to X subscribers.

Many users and advertisers alike have responded adversely to the site’s new charges for previously free services, as well as its changes to content moderation and the return of previously banned far-right accounts.

Musk also killed off the Twitter logo, replacing its globally recognized blue bird with a white X.

On Tuesday, multiple users responded to Musk’s post saying they did not see the feature in their app, which was also not visible in a version tested by AFP.