Update backuprestoreroot-list-siteprotectionunits.md

Author: DarkKnight1302

api-reference/v1.0/api/backuprestoreroot-list-siteprotectionunits.md

@@ -51,6 +51,10 @@ If successful, this method returns a `200 OK` response code and a [siteProtectio
 
 For a list of possible error responses, see [Backup Storage API error responses](/graph/backup-storage-error-codes).
 
+> [!NOTE]
+> `siteName` and `siteWebUrl` properties are currently available **only** for `Delegated` permission type.
+>
+
 ## Examples
 
 ### Example 1: List all the siteProtectionUnits in a tenant