I want to install Telegram but get the message “This device cannot be added from the UI. You can add this device by adding it to your ‘configuration.yaml’. See the documentation for more information.”
There is no explanation in the documentation. They go straight into bots.
Should the installation be done in the CLI? Can anyone give me information?
No, since this is not something you set up by using the GUI (yet? more and more integrations get that feature) you need to add it to your configuration.yaml file. If you click the links in the documentation you get the how-to there. Configuration.yaml - Home Assistant
Telegram is an online service, you can’t install that yourself. The integration is already there, as part of HA core. It is simply called a bot because it is software that can post messages.Once configured through yaml, you can use it in automations.