I understand the importance of being able to create Work Orders in QuickBooks Online (QBO), @rl43.
Though this feature is currently unavailable in QBO, you can use either the Estimate or Delayed Charge feature to record your transactions. They are non-posting entries that look similar to work orders and invoices.
Here's how you can record them in QBO:
Go to the New (+) icon from the left pane.
Select either Estimate orDelayed credit under Customers.
Fill in the necessary information from the transactions page, then save them.
For more information about entering estimates or delayed credits, check out these articles: