SSH Login Telegram Notifier

This script sends a Telegram notification whenever someone logs into your server via SSH.

Requirements

Create a Telegram bot: You can do this via BotFather.
Create a Telegram channel: This can be private or public, depending on your preference. This is where the alerts will be sent.
Get the bot updates: Create a URI in the following format:
```
https://api.telegram.org/bot*****:***-*****************/getUpdates
```
and invoke it.
Add your bot to the channel: This will allow the bot to send messages to the channel.
Get the channel ID: You can do this by visiting https://api.telegram.org/bot*****:***-*****************/getUpdates again. The channel ID will be listed there.
Register at IPInfo: You can do this at ipinfo.io. This will give you an API token.
Update the script: Fill in the variables in the script with your Telegram bot token, channel ID, and IPInfo token.
Make the script executable: You can do this with the following command:
```
chmod +x ssh_notifier.sh
```
Test the script: Run the script and check that everything works correctly.
Update the SSHD PAM configuration: Add the following line to the end of /etc/pam.d/sshd:
```
session optional pam_exec.so type=open_session seteuid /full/path/to/ssh_notifier.sh
```
This will run the script whenever someone logs into your server via SSH.

Now, try connecting to your server via SSH. You should receive a notification in your Telegram channel. Enjoy your new notification system!