Update virtualeventtownhall.md

Author: halleclottey-msft

api-reference/beta/resources/virtualeventtownhall.md

@@ -41,7 +41,7 @@ Inherits from [virtualEvent](../resources/virtualevent.md).
 | description | [itemBody](../resources/itembody.md) | Description of the town hall. Inherited from [virtualEvent](../resources/virtualevent.md). |
 | displayName | String | Display name of the town hall. Inherited from [virtualEvent](../resources/virtualevent.md). |
 | endDateTime | [dateTimeTimeZone](../resources/datetimetimezone.md) | Date and time when the town hall ends. The **timeZone** property _can_ be set to any of the time zones currently supported by Windows. For details on how to get all available time zones using PowerShell, see [Get-TimeZone](/powershell/module/microsoft.powershell.management/get-timezone#example-3-get-all-available-time-zones). Inherited from [virtualEvent](../resources/virtualevent.md). |
-| externalEventInformation | [virtualEventExternalInformation](../resources/virtualeventexternalinformation.md) collection | The external information of a town hall. |
+| externalEventInformation | [virtualEventExternalInformation](../resources/virtualeventexternalinformation.md) collection | The external information of a town hall. Returned only for event organizers or coorganizers. |
 | id | String | Unique identifier of the town hall. Inherited from [virtualEvent](../resources/virtualevent.md). Read-only. |
 | invitedAttendees | [identity](../resources/identity.md) collection | The attendees invited to the town hall. The supported identities are: [communicationsUserIdentity](../resources/communicationsuseridentity.md) and [communicationsGuestIdentity](../resources/communicationsguestidentity.md). |
 | isInviteOnly | Boolean | Indicates whether the town hall is only open to invited people and groups within your organization. The **isInviteOnly** property can only be `true` if the value of the **audience** property is set to `organization`. |