Clarify audit log S3 region access requirements (#61655)

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: kyanny <10515+kyanny@users.noreply.github.com>

Author: Copilot

content/admin/monitoring-activity-in-your-enterprise/reviewing-audit-logs-for-your-enterprise/streaming-the-audit-log-for-your-enterprise.md

@@ -79,7 +79,11 @@ You can stream audit logs to multiple endpoints. For example, you can stream you
 
 {% ifversion ghes %}
 
->[!NOTE] The Amazon region `us-east-1` must be reachable from your appliance for streaming to S3 to work. Your S3 bucket can reside in other AWS regions.
+> [!NOTE]
+> For streaming to S3, the AWS region that must be reachable depends on the option you select for the bucket's region.
+>
+> * If you select **Auto Detect**, `us-east-1` must be reachable from your appliance because the AWS SDK uses that region to detect the destination bucket's region.
+> * If you select a specific region, the selected region must be reachable from your appliance. `us-east-1` does not need to be reachable unless it is the selected region.
 
 {% endif %}
 
@@ -113,10 +117,10 @@ From {% data variables.product.prodname_dotcom %}:
 1. Under "Authentication", click **Access keys**.{% endif %}
 1. Configure the stream settings.
 
-    - Under "Region", select the bucket's region. For example, `us-east-1`.
-    - Under "Bucket", type the name of the bucket you want to stream to. For example, `auditlog-streaming-test`.
-    - Under "Access Key ID", type your access key ID. For example, `ABCAIOSFODNN7EXAMPLE1`.
-    - Under "Secret Key", type your secret key. For example, `aBcJalrXUtnWXYZ/A1MDENG/zPxRfiCYEXAMPLEKEY`.
+    * Under "Region", select **Auto Detect** or select the bucket's region. For example, `us-east-1`.
+    * Under "Bucket", type the name of the bucket you want to stream to. For example, `auditlog-streaming-test`.
+    * Under "Access Key ID", type your access key ID. For example, `ABCAIOSFODNN7EXAMPLE1`.
+    * Under "Secret Key", type your secret key. For example, `aBcJalrXUtnWXYZ/A1MDENG/zPxRfiCYEXAMPLEKEY`.
 {% data reusables.audit_log.streaming-check-s3-endpoint %}
 {% data reusables.enterprise.verify-audit-log-streaming-endpoint %}