"VT-x not available" when attempting to launch a Vagrant VM in Virtualbox in Parallels Mac VM

I have a Parallels VM running Mojave 10.14.2 and I'm trying to run a Vagrant VM via Virtualbox within this Mac VM. Whenever I try to launch the Vagrant VM, Virtualbox fails with the error "VT-x is not available." After looking though different documentation, including https://kb.parallels.com/en/116239, I can't tell if nested VMs is straight up not allowed on a guest Mac VM (because the "enable nested virtualization" checkbox doesn't exist when I looked) or if I need Parallels Desktop 14 for Mac Pro Edition to enable that feature. Some clarification would be greatly appreciated. Thanks!

I'm using Virtualbox 5.2.26 and Parallels Desktop 14 for Mac Business Edition (14.1).

 

Try in command line:
$ prlctl set "$vm_name" --nested-virt on

 

That did the trick; my VM started successfully. Hopefully it'll be stable for my purposes. Thanks for the tip!