This snap will only work on Wayland compositors, but doesn't require Ubuntu Frame specifically. For example, it can be used on GNOME/Wayland by running mir-kiosk-neverputt, but that isn't the intended use.
When used on Ubuntu Core, mir-kiosk-neverputt will automatically run as a daemon on startup. If building an embedded system based on another OS then you may need to enable the daemon with:
Swap out openSUSE_Leap_15.5 for openSUSE_Leap_15.4 or openSUSE_Tumbleweed if you’re using a different version of openSUSE.
With the repository added, import its GPG key:
sudo zypper --gpg-auto-import-keys refresh
Finally, upgrade the package cache to include the new snappy repository:
sudo zypper dup --from snappy
Snap can now be installed with the following:
sudo zypper install snapd
You then need to either reboot, logout/login or source /etc/profile to have /snap/bin added to PATH.
Additionally, enable and start both the snapd and the snapd.apparmor services with the following commands: