The tutorial you've seen is intended for QuickBooks Desktop, Daniel.

This is the reason why you can't see it in your account since you're using QuickBooks Online. No worries, I'll share the steps with you on how you can customize the email templates in the version that you're using. Here's how:

1. Click the Gear icon in the upper-right hand corner of the desktop app.
2. Select Account and settings and proceed to the Sales tab.
3. Look for Messages and click on it.
4. Select a sales form in the drop-down list for Sales form.
5. Customize the email message and enter any other details.
6. Click Save, then click Done.

Let me also share article with you for more guidance about using the desktop app: General Support For QuickBooks App for Windows and Mac.

You can always reach out to us anytime you need help. We're always here to be your guide.