[Question] How to integrate sendgrid API into Lemmy Ansible installation?

I'm using the Lemmy ansible installation method. I've been trying to add sendgrid to the postfix section of the config.hjson file on my local machine. But where do I add the API key and username? I used port 587 but nothing works. Can anyone help walk me through how to integrate sendgrid into Lemmy-Ansible? Thanks!!

the email section of config.hjson looks like this, did I do this right?

  email: {
    smtp_server: "smtp.sendgrid.net:587"
    smtp_from_address: "noreply@{{ domain }}"
    tls_type: "tls"
  }

I was able to find the server location on my VPS under srv/lemmy/domain, so I can edit the lemmy.hjson file there if need be.