docs(add): faq billing question

Author: nerda-codes

pages/audit-trail/faq.mdx

@@ -3,7 +3,7 @@ title: Audit Trail FAQ
 description: Get answers on using Scaleway's Audit Trail to monitor events, enhance security, and track activities across your resources
 productIcon: AuditTrailProductIcon
 dates:
-  validation: 2025-08-18
+  validation: 2025-11-10
 ---
 
 ## Overview
@@ -29,6 +29,10 @@ Find out more about product availability in the [dedicated documentation](/accou
 ### How am I billed for using Audit Trail?
 Audit Trail is free of charge.
 
+### How am I billed for Audit Trail exports to an Object Storage bucket?
+
+Audit Trail exports are free of charge but using Object Storage may incur additional charges. Refer to the [Object Storage FAQ](/object-storage/faq/#how-am-i-billed-for-object-storage) for more information on pricing.
+
 ## Compatibility and integration
 
 ### Which Scaleway products are integrated with Audit Trail?