Telegram

Thank you to snis for these instructions.

First you must create a telegram account and add BotFather to you list. To do this click on the following url: https://telegram.me/botfather
Generate a new bot with the command "/newbot" BotFather is then asking for a username and a normal name. After that your bot is created and you get a HTTP token. (for more options for your bot type "/help")
Add your bot to telegram with the following url: http://telegram.me/<botname> to use app or https://web.telegram.org/<botname> to use in web, and send some text to the bot.
The BotFather should have responded with a token, copy your token code and go to the following page in chrome: https://api.telegram.org/bot<tokencode>/getUpdates (this could take a while so continue to refresh until you see something similar to below)
You see a json code with the message you sent to the bot. Copy the Chat id. In this example that is “-9787468” within this example: "message":{"message_id":7,"from":"id":656556,"first_name":"Joo","last_name":"Doo","username":"JohnDoo"},"chat":{"id":-9787468,"title":"Telegram Group"},"date":1435216924,"text":"Hi"}}]}.
Now create a new "Telegram transport" in LibreNMS (Global Settings -> Alerting Settings -> Telegram transport). Click on 'Add Telegram config' and put your chat id and token into the relevant box.
If want to use a group to receive alerts, you need to pick the Chat ID of the group chat, and not of the Bot itself.

Example: