Most people don't seriously consider regular backups as a necessity until they have experienced a significant data loss. You should create your own backup strategy to protect yourself from data loss. Virtual machines are as vulnerable to crashes as physical computers.
You can back up your virtual machine using one or several of the following methods:
Configure the regular backup settings on the Backup tab of the Virtual Machine Configuration dialog.
Use third-party backup utilities.
Clone the virtual machine with the help of Cloning Virtual Machine Assistant. Give a descriptive name to the clone and save it in a location specially designated for backups.
Copy the virtual machine files manually.
On the Backup tab of the Virtual Machine Configuration dialog, you can choose how to back up your virtual machine regularly. You can configure how the virtual machine snapshots will be created or choose to back up the virtual machine with Time Machine.
If you choose to back up your virtual machine with Time Machine, your virtual machine's PVM file will be automatically backed up together with other files stored in macOS. As a consequence, files stored on your virtual machine's hard disk will be also backed up, since the virtual hard disk file (HDD) is stored inside the virtual machine bundle file (PVM).
Warning: Time Machine backups can guarantee safety only when your Parallels virtual machines were stopped or suspended during the backup.
You can use any third-party backup utilities you like.
You can create a complete clone of a virtual machine using Clone Virtual Machine Assistant. For details, see Cloning a Virtual Machine.
You can locate your virtual machine in Finder and create a backup copy of the virtual machine file (PVM).
In Control Center (or in the virtual machine window if it is shut down), right-click the virtual machine name and select Show in Finder from the context menu. In Finder, go to the folder where your virtual machine is stored.
Locate the required virtual machine PVM file. Note: PVM file is a bundle that contains the virtual machine configuration file (PVS), virtual hard disk file (HDD), and other files. For more information about the virtual machine files, see About Virtual Machines.
Copy the virtual machine's PVM file to a safe location.