SMTP Notifier -- How to Customize Target Recipients?

Sorry for the stupid question, but perhaps I’m not seeing this the right way.

I have a notifier that works fine with 1 recipient:

name: smtpmail
platform: smtp
server: smtp.office365.com
port: 587
timeout: 15
starttls: true
username: !secret notification_username
password: !secret notification_password
sender: !secret notification_sender
#recipient:
#  - !secret notification_recipient
sender_name: My Assistant

But in my automations, I want to send SMTP Notifications to target multiple recipients?

How can I over-ride the recipients? Do I build a Helper List?

Thanks In Advance,
~Bryan

recipient:
  - zaphod@heart_of_gold.com
  - [email protected]
  - ford_prefect@megadodo_publications.com

Hi Tom,
Thank you for the response and detail.
Just to clarify, can I add the target inside the Visual Automation UI or do I have to add to .yaml?
Thank you,
~Bryan

SMTP has to be set up using YAML. There is no UI version.

Got it! Thank you, Tom.

For others who may read this in future:

In notifier:

name: smtpmail
platform: smtp
server: smtp.office365.com
port: 587
timeout: 15
starttls: true
username: !secret notification_username
password: !secret notification_password
sender: !secret notification_sender 
recipient:
  - !secret notification_recipient  #  This is default recipient needed for smtp notifier to load.  Can be overridden by target in automation (see below).
# Within the Automation YAML
data:
  title: "⚠️ Shopping Reminder"
  message: |
    Don't Forget the Milk!{{"\r\n"}}
  target:
    - [email protected]
    - [email protected]
  data:

Kind Regards,
~Bryan