How do I get the recipient’s name to show e.g. “Hello Bob” in an email template when you are sending the email from the UI?

Hope this helps! You need to use merge fields in your email template. For the recipient name, use something like {entity.firstname} or {entity.entityid} depending on what field you want to pull. In the template editor, you can add "Hello {entity.firstname}" and it'll populate when you send. The exact field depends on whether you're emailing customers, contacts, vendors, etc. You can see all available merge fields by clicking the field dropdown in the template editor.

entity.firstName is what we have and it doesn’t work. We don’t want the entity field from the record, we want the RECIPIENT who may not be in any field on the record.