Reasoning: To ensure the app can recognize and retrieve properties from invoices using Azure AI Search, you need a service that specializes in analyzing and extracting data from structured documents like invoices. Azure AI Document Intelligence (formerly known as Azure AI Document Intelligence) provides pre-built models for processing invoices, extracting fields such as invoice numbers, dates, totals, and more. You can integrate Azure AI Document Intelligence with Azure AI Search by adding a custom skill to the search pipeline, allowing the app to extract and index specific properties from invoices. This ensures that App1 can retrieve relevant content from the invoices efficiently.