Even if you use the distro apps for WSL you can upgrade to the latest release.

The following steps did the trick:

Verify your release before the upgrade

cat /etc/lsb-release
  1. Apply all updates of installed packages
sudo apt update
sudo apt upgrade -y
  1. Remove unused Kernels and install ‘update-manager-core’
sudo apt --purge autoremove
sudo apt install update-manager-core -y
  1. Start Upgrade Process
sudo do-release-upgrade

As the Linux environment apps such as Ubuntu or Debian do not support the Systemd that provides fundamental building blocks for a Linux operating system, we can’t use reboot or use the systemctl commands to manage the systemd services. So in order to restart WSL we need to restart the Lxssmanager service.

Get-Service LxssManager | Restart-Service

Verify your release after the upgrade

cat /etc/lsb-release