Solved it by finding the git repository: DamionGans/ubuntu-wsl2-systemd-script: Script to enable systemd support on current Ubuntu WSL2 images [Unsupported, no longer updated] (github.com)
on Running Snaps on WSL2 (Insiders only for now) - snapd - snapcraft.io
Also i needed to reinstall snapd ( see Bug #1826662 “Can’t install any snaps: too early for operation, …” : Bugs : snapd (launchpad.net)):
1. $ sudo service snapd stop
2. $ sudo apt purge snapd
3. $ sudo apt install snapd
EDIT
I have tried to built the snap in destructive mode, otherwise i get a VM error:
Launching a VM.
launch failed: CPU does not support KVM extensions.
An error occurred with the instance when trying to launch with 'multipass': returned exit code 2.
Ensure that 'multipass' is setup correctly and try again.
But also in destructive-mode i get an error:
...
Get:1 libpng16-16_1.6.37-2_amd64.deb [179 kB]
Fetched 179 kB in 0s (0 B/s)
Sorry, an error occurred in Snapcraft:
[Errno 1] Operation not permitted
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