Sure. There are 2 ways:
1.) use bhyve to install Proxmox Backup Server inside a VM. I use 4GB RAM, 4 threads, 32GiB disk and UEFI for the VM. I wasn't able to get the PBS ISOs installer running with bhyve but installing Debian 10 Buster and PBS packages ontop of it worked fine. The benefit is that this will allow you to do incremental backups with deduplication. So the backups consume way less space and are faster done.
2.) use a NFS or SMB share as a vzdump backup storage. Here you don't need to run a VM but every backup will consume the full (compressed) size of the whole VM and the whole VM needs to be transfered.
I use a mix of both. PBS for automated daily backups and vzdump for manual backups.