Render an email template preview

curl -X POST 'https://api.expiryedge.com/v1/emailTemplatePreview' \
  -H "Authorization: Bearer $EXPIRYEDGE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "subject": "Reminder: {{expiry.name}} {{expiry.status}}",
  "body_html": "<p>{{expiry.name}} {{expiry.status}}.</p>"
}'

{
  "subject": "Reminder: Acme Insurance Policy expires in 14 days",
  "html": "<p>Acme Insurance Policy expires in 14 days.</p>",
  "text": "Acme Insurance Policy expires in 14 days."
}