OVMF/UEFI Boot Entries - Proxmox VE
https://pve.proxmox.com/wiki/OVMF/UEFI_Boot_EntriesStart-up the VM and press ESC to get into the OVMF menu. Then "Boot Maintenance Manager" -> "Boot Options" -> "Add Boot Option" -> choose Disk with the Efi System Partition. Now find the EFI executable, for example for Debian: EFI/debian/grubx64.efi or for Fedora: EFI/fedora/shimx64-fedora.efi. Name it ("Input the description") and "Commit Change".