You're looking at a list of different builders.
there can be multiple builder entries, and they're indicated by a certain 'type' - see the field named type.
In the example from Stefan there are qemu, hyperv-iso, vmware-iso, virtualbox-iso and finally parallels-iso.
Each of them contains
a full set of parameters for building a VM "artifact"
This was answered via StackOverflow by Kevin Lu:
In short, the second suggestion he made to update to PowerShell 7 and adding the environment information worked. I also had to run the script to reregister the Azure agent on the target server.