The waitingforkey event is fired at a media element when it is first unable to play because it needs a key to decode the following data, and playback is stopped.
If the video frame and/or audio data for the current playback position have been decoded, readyState is set to HAVE_CURRENT_DATA. Otherwise, including if the data was previously available but isn't anymore, the readyState is set to HAVE_METADATA.
Use the event name in methods like addEventListener(), or set an event handler property.
addEventListener("waitingforkey", (event) => { })
onwaitingforkey = (event) => { }An Event.