Now the plugin works. Thanks.

No solution yet.

My objective was to have Shelly cloud enabled AND having my Shellies working within Domoticz.

Now I'm using MQTT, but it's not supported simultaniously with Shelly Cloud enabled. And it doesn't look like they will change this for all shellies in the near future.

A bit of a shame...

Missing a basic installation manual. This is what I did on my debian10 VM running Domoticz 2022.1;

logged in as root on console;

cd /home/Domoticz/plugins
git clone https://github.com/mario-peters/ShellyCloudPlugin.git ShellyCloudPlugin

cd ShellyCloudPlugin
chmod +x plugin.py

apt-get install ...