Telegram Bot sending messages. Source: https://bogomolov.tech/Telegram-notification-on-SSH-login/

telegram-send.sh

#!/bin/bash

GROUP_ID="xxxx"
BOT_TOKEN="xxxx"

# this 3 checks (if) are not necessary but should be convenient
if [ "$1" == "-h" ]; then
	echo "Usage: `basename $0` \"text message\""
	exit 0
fi

if [ -z "$1" ]; then
	echo "Add message text as second arguments"
	exit 0
fi

if [ "$#" -ne 1 ]; then
	echo "You can pass only one argument. For string with spaces put it on quotes"
	exit 0
fi

curl -s --data "text=$1" --data "chat_id=$GROUP_ID" --data "parse_mode=html" 'https://api.telegram.org/bot'$BOT_TOKEN'/sendMessage' > /dev/null