If If you are able to retrieve the broken piece from the lock, you can order replacement keys here.
If you are not able to retrieve the broken piece of key from the lock and need to replace the lock, locks can be ordered here
If you require access to your cash drawer to retrieve the insert tray before you are able to get replacement parts, you can manually open your cash drawer by removing the case, watch these videos for details on how to remove the case. Please refer to the video below for the cash drawer product you own.
Vasario Cash Drawer Series
Series 100 Cash Drawer
Series 4000 Cash Drawer