How do I include the customer email address on the invoice?

It's good to have you here, @logistics-proaut.

I can definitely help you add email addresses on your invoices. You can do this by updating the customer's profile and adding their email on the address section. This is the default field on the invoice so it will appear on the template.

Here's how:

1. Click the Sales menu, then Customers.
2. Tap the customer name and click Edit.
3. Go to the Addresses section and add the email from there.
   
4. Once done, save the transaction. Here's how it looks like when you send or print the invoice:
   

Here are some related links that will help  you with customising sales templates and other program tutorials:

• Customise invoices, estimates, and sales receipts in QuickBooks Online
• QBO Tutorials

Please post here again if you need further help with anything with QuickBooks. You can also mention me anytime if you have other questions with adding information to your customers or modifying the sales templates. I'll be more than happy to help.