proxmox_vm_start_at_boot_and_auto_shutdown

VM Auto Start (Start At Boot)

Select the VM
Click the menu Options
Double click the Start at boot
Check Start at boot and click OK
Click the menu Start/Shutdown order (Proxmox starts VMs in ascending order, and shuts VMs down in reverse order)

VM Auto Shutdown

First, we must install QEMU Guest Agent

apt install qemu-guest-agent

Find the menu QEMU Guest Agent, make sure it's enabled
If enabled, when the host shuts down, Proxmox will send a proper shutdown command to the VM