api.getParticipantsInfo() is not working

Hi, am using IFrame API.
api.getParticipantsInfo(); is not working for me. Am trying to get the participant with in readytoclose event listner. But am getting following error.
My code
api.addEventListener(‘readyToClose’, function(){

		api.getParticipantsInfo();
		
		api.dispose();
		

	});

Error
api.getParticipantsInfo();
VM14166:1 Uncaught TypeError: api.getParticipantsInfo is not a function.

Please guide me to resolve this issue

I’m getting the same error when using my local external_api.js, however when I use the one provided at https://meet.jit.si/external_api.js, it works as expected.

I have deployed Jitsi via Docker, using stable release 4857.

EDIT: Apparently, that feature was added as recently as 16 days ago, and is not yet present in the Docker releases.

I’m using the current latest stable version (4428 / docker release stable-5076) and the command is executed without errors, but it returns an empty array even containing participants in the room. Do I need authentication with Prosody for this feature???