With custom checkout field you can collect additional details from customers.
In the Store tab select Design > Pages > tap on Checkout
Tap on +Add question
Field title - displayed as label
Description - a hint for a customer
Answer required - enable this to make field mandatory
Additional field will appear at the order placement page. You can add up to 8 custom fields.
Please note that a large number of fields can complicate the checkout process.
Customer will see custom field at the bottom and need fill out upon adding information.
On the Checkout page they can edit the message if needed.
You will see customer notes in Order details