Computer Configuration > Administrative Templates > Microsoft Edge
Both
HKLM\Software\Policies\Microsoft\Edge
Specifies URL patterns for sites that aren't allowed to request access to a serial port. If not configured, Microsoft Edge uses the value from the DefaultSerialGuardSetting policy (if set), or the user's settings. For unmatched sites, the following order applies: 1. SerialAskForUrls (if matched). 2. DefaultSerialGuardSetting (if set). 3. User's settings. URL patterns in this policy must not conflict with those in SerialAskForUrls. This policy takes precedence. For detailed information about valid URL patterns, see https://go.microsoft.com/fwlink/?linkid=2095322. Example value: https://www.contoso.com [*.]contoso.edu