3 lever mortice lock, looks like an ERA keyway. If you can take it out, take it to a proper locksmith shop and they’ll make you a key. Then you can try the key in all the others, but I would guess they’re keyed to differ.
You aren’t going to be able to just order one online though. If you want keys you need a locksmith, but if I am correct on the lock ID, replacing them is probably cheaper than getting keys made. The locksmith will give you your options.