How to add note to an order?

In the order section, notes can be added to record additional information, instructions, reminders, and more. After placing an order, any customer or seller can add a note to it for context or internal reference.

Orders section is available only in Customer View (logged-in on behalf of the Customer organization):

Customer, Customer admin, Account manager, Seller admin, Distributor admin can add a note to an existing Recent and Historical order. 

Once an order note is added it is read-only. Note! After a note is saved, it can't be edited.

Orders can be filtered by the order note: