There is no direct conversion_value field available in Apple Search Ads data. Alternatively, users may be able to leverage the sales_purchasable_item_source_type_report table from the Apple App Store connector, which tracks app and in-app purchases. The sales field, when filtered by source_type = 'App Store Search', provides insights into purchases originating from App Store searches. See Apple's Sales and Trends metrics and dimensions Doc for more details.
Currently, our Apple App Store package does not utilize the sales_purchasable_item_source_type_report table. Go to this Github Issue section to join the discussion.