mariandz

After creating your personal Telegram bot, you can use the following features: 
– Add the bot to multiple chats and groups 
– Get notifications upon new posts and comments 
– When WooCommerce is installed, you can also get notifications about new orders and reviews 
– Edit and change status of posts, comments, orders, and reviews 
– Browse through the latest posts, comments, orders, and reviews 
In case you are missing any features or have found a bug, just let me know.

TeleAdmin

Manage your WordPress site on the way using Telegram. Receive notifications, accept comments and edit WooCommerce orders.

nikita.global

Create your own notification bot which will send emails to your dashboard users via telegram.
Sends all mails to telegram user via your own bot. 
No need in many other plugins as you can use any email notifications which will be redirected to telegram
<a href="https://nikita.global" rel="nofollow ugc">https://nikita.global/</a>
Your website should support https.
** Message Filters ** 
Currently can send mails as plaintext, files, subjects only and truncated message. 
You can extend this range using the filters – see source code.
This plugin makes HTTP-requests to 3rd party service <a href="https://core.telegram.org/api" rel="nofollow ugc">Telegram API</a> 
to send notifications.

NG-Mail2Telegram

very good!

Create your own notification bot which will send emails to your dashboard users via telegram.

TeleAdmin vs NG-Mail2Telegram