In which scenario should you embed a flow using Lightning Out?

Embedding a flow using Lightning Out is particularly useful when integrating with an external application. This approach allows seamless interaction between Salesforce flows and external applications by making use of the Lightning Component framework, which enables the flow to be displayed on external pages or applications that are not part of the Salesforce environment.

By using Lightning Out, you can extend the capabilities of Salesforce flows to users who may not have direct access to Salesforce or allow those flows to interact with external data or processes. This opens up opportunities for businesses to streamline workflows and enhance user experiences across different platforms.

In contrast, embedding a flow in a report dashboard, building a Lightning app, or designing a Visualforce page does not require the unique capabilities that Lightning Out provides, as these scenarios are typically contained within the Salesforce platform. Therefore, for external integration to be effective and user-friendly, utilizing Lightning Out is the ideal solution.