I'm trying to add a "Send Email" step to my journal entry approval workflow that will send an email to the creator of the JE from the next approver field once approved. I keep running into errors saying "The author internal id or email must match an employee." I've been trying to use the created by field either as the join (and then selecting email as the field) or the current record as the join and then created by as the field. I get the same error message. What field should I use instead?