This chrome-extenshon opens www.telegram.org in Popup page Side Panel
Using https://web.telegram.org in Chrome is not safe.
When you open https://web.telegram.org, other installed Chrome extensions (like e.g. adblock) can read your chats, as they have full access to any opened tabs. I.e. they can read all content in your Telegram tab and send it to 3rd party servers.
Telegram-in-popup-chrome opens Telegram app in so called Popup window - this is special, secured context, kind of sandbox in Chrome, not accessible from any other Chrome extensions. This extension is basically just specially configured manifest.json, there is no JS code inside - i.e. there is no even technical possibility to steal your private data from Telegram webpage.
As Google rejected this extention due to Policy vioation (they don't allow to publish extensions with only functionaty to open 3rd party website) - the only option is to install it manually (see how-to below)
- Clone the repo
- Open
chrome://extensions
in chrome - Toggle
Developer mode
- Load unpacked > choose
src
folder