In order for fivetran to read from our database we need to configure logical replication on our read replica db. 

All tables should should be enabled for publication and a replication_slot created.

Start at step 4:
https://fivetran.com/docs/connectors/databases/postgresql/rds-setup-guide#configureincrementalupdates

Done:

• Cron Job that run's necessary sql using a superuser (app default should work)
• Replication slot created
• Publications created
• Fivetran user granted access to rds_replication