Microsoft's new Edge browser built on Chromium is now available in beta. But by default, you can only install a small number of Microsoft-approved extensions. To install extensions from the Chrome Web Store in the new Edge.
Only for the new chromium-based frame
Microsoft is testing a new version of Edge that dumps its rendering engine for the benefit of Chromium, which underlies Google Chrome. Chrome gets better battery life and the new Edge gets Chrome extensions. Microsoft hosts some Edge-specific extensions, but only about 100 of them. It sounds like a lot, but when you throw out duplicate functionality and a little small add-ons (like Microsoft Personal Shopping Assistant), it reduces the list. It grows, but compared to the Chome Web Store it is quite small.
So if you use the new Edge and want more browser extensions, you can install them from the Chrome Web Store. And that's good, because even if an extension is in both the Edge and Chrome stores, the Chrome version sometimes works better or has more features. For example, we cannot get the Grammatical Edge extension to log into an account to unlock Premium features. But the Chrome add-on installed on the Edge works just fine.
To install Chrome add-ons, all you have to do is turn a switch and browse to the online store. But you should be aware of a few warnings from Microsoft: If an add-on is based on Google account functionality to log in or sync, then the extension may not work in the Edge. If the extension is based on companion software on the computer, the extension may not work, even if you installed the software.
How to install Chrome Extensions in Edge
Installing Chrome Extensions on Edge is a sincere affair. First click on the three horizontal points in the upper right corner of the browser to open the menu.
Then click "Extensions" in the menu. 
Enable "Allow other stores to add" in the lower left corner of the Extensions page that appears.
Microsoft will warn you that it has not verified the extensions in the Chrome Web Store or anywhere else online. Click "Allow" to continue.
Browse now for the Chrome Web Store and find an extension you want to install. All you have to do is click on "Add to Chrome."
Click "Add extensions" in the confirmation dialog – just as if you installed the extension in Chrome.
Remember that any extensions you installed from the Chrome Web Store were not tested for the Edge browser. You may experience errors or other crimes. It may be wise to install an extension at a time and make sure you have no problems before moving to the next extension.