Hello @user2402! We are extremely glad to greet you in our Community! Welcome 
Unfortunately, there is no option to display Telegram room in our widget. I am so sorry 
Our widget is basically an interface that connects your website to Telegram. So when you click Start Chat, you get redirected to the mobile or desktop Telegram messenger, and the chat takes place on Telegram side.
We have such a request in our Wishlist. Please vote for this feature to get a notification upon its release -Include an option to display the live telegram chat room feedIO
If any other questions come up, please feel free to contact us.
Have a great day 