Subject lines for Shopify notification emails are edited in Shopify, not inside the UpOrder template builder.
UpOrder controls the design and content of the notification template body that you publish to Shopify. Shopify stores the email subject separately in each notification template, so subject line changes need to be made from your Shopify admin.
Before you start
Shopify requires your sender email address to be confirmed before you can edit the subject heading or body of notification emails. If Shopify prompts you to confirm your sender email, follow that prompt first.
How to update a subject line
1. From your Shopify admin, click Settings.
2. Click Notifications.
3. Click Customer notifications.
4. Open the notification you want to edit. For example, Order confirmation. Then click Edit code.
5. Update the Email subject field, then click Save.
Testing your subject line
After saving, use Shopify's preview or send a test email from the notification editor to confirm the subject line appears the way you expect. Shopify sends test emails to the admin account you used to log in.
A few helpful notes
Subject lines are template-specific. If you want to update the subject for multiple notification emails, repeat these steps for each notification.
You can use Shopify Liquid variables in subject lines, but make sure to test them carefully. A variable can appear blank if that data is not available for the notification being sent.
If you are trying to change the preview text that appears beside or underneath the subject line in some inboxes, see: How do I change the preview text for my notification emails?
For Shopify's full notification editing guidance, see: Customizing email notification templates.
Please reach out to [email protected] or through the in-app chat if you have any questions.