How to define External ID on Salesforce Upsert block

New Scribe Online user here. I'm working to connect two Salesforce orgs together in a single direction, pulling new and updated records from one org to another. I've got my native query, but am stuck on the Upsert block. How do I define what field to use as the External ID? I'm mapping the native Salesforce Record ID from the source org to a custom external ID field in my destination org. I have multiple External ID fields in my destination org.

(5) Answers