fetch
Fetches a previously uploaded base64 file and returns its content.
Requires a joined room.
Throws
code 3073 (ERROR_INVALID_PARAMETER) if any argument is empty, 3035 / 3065 if the room is not joined or is reconnecting, or 3075 (ERROR_FILE_FETCH_FAILED) when the request cannot be sent or the server answers with an error status, for example Fetch failed with status 402 Payment Required.. That failure also reaches RoomEventListener.onError.