Where is Location of Microsoft Edge Extension Folder that are installed from Microsoft Store?

Since extensions are appx packages, try C:\Users\%username%\AppData\Local\Packages. Search for the folder starting with the extension name.

Edit: Actual source code is in the C:\Program Files\WindowsApps You might need to change folder owner to yourself to gain access.

In your edge browser go to edge://version/ page and locate the Profile Path there that would look something like C:\Users\%username%\AppData\Local\Microsoft\Edge Beta\User Data\Default

Its located under

C:\Users\admin\AppData\Local\Microsoft\Edge\User Data\Default\Extensions