Computer Configuration > Administrative Templates > Microsoft Edge
Both
HKLM\Software\Policies\Microsoft\Edge
OBSOLETE: This policy is obsolete and doesn't work after Microsoft Edge 91. When this setting is enabled, Microsoft Edge allows connections secured by SHA-1 signed certificates so long as the the certificate chains to a locally-installed root certificate and is otherwise valid. Note that this policy depends on the operating system (OS) certificate verification stack allowing SHA-1 signatures. If an OS update changes the OS handling of SHA-1 certificates, this policy might no longer have effect. Further, this policy is intended as a temporary workaround to give enterprises more time to move away from SHA-1. This policy will be removed in Microsoft Edge 92 releasing in mid 2021. If you don't set this policy or set it to false, or the SHA-1 certificate chains to a publicly trusted certificate root, then Microsoft Edge won't allow certificates signed by SHA-1. This policy is available only on Windows instances that are joined to a Microsoft Active Directory domain, Windows 10 Pro or Enterprise instances that enrolled for device management, or macOS instances that are that are managed via MDM or joined to a domain via MCX.