Hello there, Michelle.

There's an easy way of adding notes to invoices or statements.

You can add this as a footer in where there are two places where you can put in a customer message, as default.

Let me show you how:

1. Click on the Gear icon at the top, then Custom Form Styles.
2. Choose New style or choose the type of transaction you want to customize.
3. Click on Content.
   
4. Click the boxes under Invoices and other sales forms or Add payment details and footer to enter any information.
   
5. Save changes.
   

Attached is a screenshot so you can see exactly what I'm referring to.

Other option is import your custom form style.

Please let me know if you're able to edit the template after trying the steps. Thank you!