There is the counterpart just below the lid held in place by a screw or 2. Undo those, place in lid lock.
Or, if you want to keep the lid lock working for the rest of the time when you aren't watching (which you should for safety reasons), you can just order that part. It's only a few bucks and about the size of a small toy car maybe and can be kept near the machine without anybody else then being abled to figure out what it is for thus keeping them safe.