I have a Classic email template that I call via an email alert in process builder. Because I want a non-letterhead look and need HTML features, I converted the Classic email template to a Lightning email template. This works fine if I don't have any merge fields in the template. However, I want to have the contact's first name in the template. I decided to call the alert via a Flow instead of Process Builder thinking this would help as I include the Contact's id in the Flow's email alert. I get an error when the alert is called indicating that the merge field isn't available. How can I include a Contact's merge field in a Lightning template that is called via an alert in a flow?
I have tried {{{Contact.FirstName}}} and {{{Recipient.FirstName}}}. I get an error with either one.