Computer Configuration > Administrative Templates > Microsoft Edge > Content settings
Both
HKLM\Software\Policies\Microsoft\Edge
Setting the policy lets you list the URL patterns that specify which sites can ask users to grant them read access to files or directories in the host operating system's file system via the File System API. Leaving the policy unset means 'DefaultFileSystemReadGuardSetting' (Control use of the File System API for reading) applies for all sites, if it's set. If not, users' personal settings apply. URL patterns can't conflict with 'FileSystemReadBlockedForUrls' (Block read access via the File System API on these sites). Neither policy takes precedence if a URL matches with both. For detailed information about valid url patterns, see https://go.microsoft.com/fwlink/?linkid=2095322. * is not an accepted value for this policy. Example value: https://www.example.com [*.]example.edu