Optional
options: boolean | AddEventListenerOptionsOptional
options: boolean | AddEventListenerOptionsQueries if a given mode may be supported by the user agent and device capabilities.
Optional
options: boolean | EventListenerOptionsOptional
options: boolean | EventListenerOptionsAttempts to initialize an XRSession for the given mode if possible, entering immersive mode if necessary.
Optional
options: XRSessionInit
Dispatches a synthetic event event to target and returns true if either event's cancelable attribute value is false or its preventDefault() method was not invoked, and false otherwise.
MDN Reference