Computer Configuration > Administrative Templates > Microsoft Edge
Both
HKLM\Software\Policies\Microsoft\Edge
A list of URLs to which 'AutoOpenFileTypes' (List of file types that should be automatically opened on download) will apply to. This policy has no impact on automatically open values set by users via the download shelf ... > "Always open files of this type" menu entry. If you set URLs in this policy, files will only automatically open by policy if the URL is part of this set and the file type is listed in 'AutoOpenFileTypes'. If either condition is false, the download won't automatically open by policy. If you don't set this policy, all downloads where the file type is in 'AutoOpenFileTypes' will automatically open. A URL pattern has to be formatted according to https://go.microsoft.com/fwlink/?linkid=2095322. This policy does not work as expected with file://* wildcards. Example value: example.com https://ssl.server.com hosting.com/good_path https://server:8080/path .exact.hostname.com