apt update && apt dist-upgrade:
root@pve:~# apt update && apt dist-upgrade
Hit:1 http://ftp.debian.org/debian bookworm InRelease
Hit:2 http://security.debian.org/debian-security bookworm-security InRelease
Hit:3 http://ftp.debian.org/debian bookworm-updates InRelease
Hit:4 http://download.proxmox.com/debian/pve bookworm InRelease
Hit:5 http://download.proxmox.com/debian/ceph-reef bookworm InRelease
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
14 packages can be upgraded. Run 'apt list --upgradable' to see them.
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Calculating upgrade... Done
The following packages will be upgraded:
proxmox-kernel-6.5 proxmox-kernel-6.5.11-7-pve-signed proxmox-kernel-helper
proxmox-offline-mirror-docs proxmox-offline-mirror-helper pve-edk2-firmware
pve-edk2-firmware-legacy pve-edk2-firmware-ovmf pve-qemu-kvm spl ssh zfs-initramfs
zfs-zed zfsutils-linux
14 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
1 not fully installed or removed.
Need to get 0 B/138 MB of archives.
After this operation, 557 MB of additional disk space will be used.
Do you want to continue? [Y/n] Y
Reading changelogs... Done
(Reading database ... 45495 files and directories currently installed.)
Preparing to unpack .../00-proxmox-kernel-6.5.11-7-pve-signed_6.5.11-7_amd64.deb ...
Unpacking proxmox-kernel-6.5.11-7-pve-signed (6.5.11-7) over (6.5.11-7) ...
root@pve:~# grep '' /etc/apt/sources.list && grep '' /etc/apt/sources.list.d/*
deb http://ftp.debian.org/debian bookworm main contrib
deb http://ftp.debian.org/debian bookworm-updates main contrib
# Proxmox VE pve-no-subscription repository provided by proxmox.com,
# NOT recommended for production use
deb http://download.proxmox.com/debian/pve bookworm pve-no-subscription
# security updates
deb http://security.debian.org/debian-security bookworm-security main contrib
/etc/apt/sources.list.d/ceph.list:deb http://download.proxmox.com/debian/ceph-reef bookworm no-subscription
/etc/apt/sources.list.d/pve-enterprise.list:#deb https://enterprise.proxmox.com/debian/pve bookworm pve-enterprise
root@pve:~#
The system restarts as soon as the install for the kernel starts after the apt upgrade command.