Computer Configuration > Administrative Templates > Microsoft Edge > Extensions
Both
HKLM\Software\Policies\Microsoft\Edge
Define URLs that can install extensions and themes. Define URLs that can install extensions and themes directly without having to drag and drop the packages to the edge://extensions page. Each item in this list is an extension-style match pattern (see https://go.microsoft.com/fwlink/?linkid=2095039). Users can easily install items from any URL that matches an item in this list. Both the location of the *.crx file and the page where the download is started from (in other words, the referrer) must be allowed by these patterns. Do not host the files at a location that requires authentication. The 'ExtensionInstallBlocklist' (Control which extensions cannot be installed) policy takes precedence over this policy. Any extensions that's on the block list won't be installed, even if it comes from a site on this list. Example value: https://corp.contoso.com/*