Track an embedded message session and related impressions

This endpoint tracks a single <code>embeddedSession</code> event, and one <code>embeddedImpression</code> event for each of the session's impressions. <br/><br/>An <code>embeddedSession</code> event represents a period of time when a user is viewing a page or a screen where embedded messages can be displayed (in one or many placements).<br/><br/>An <code>embeddedImpression</code> event represents the number of times a given embedded message was visible during the session, and the total amount of time the message was visible (in seconds) across all those appearances.<br/><br/>This endpoint does not create events for test messages (proofs).<br/><br/>Learn about <a href="https://support.iterable.com/hc/articles/29156459027348">identifying users by <code>userId</code> and <code>email</code></a>.