if you need to set a preset text to show on the orders and inoices, you may do that on the device and web
Main menu > Settings
Settings > Sales orders >
Sales orders > Show order notes
Type the text you need to set for your orders or inovoices on the PDF
On the web version
Dashboard > Settings > Sales orders > orders
click on the label Show order notes
Type in the box the information you need to show when creating an order from the web version