Thanks for taking the time to visit the Community. I'd be glad to provide some info on your question about work order in QuickBooks Online.
You may be interested in using the Estimate feature. The Online version of QuickBooks doesn't specifically refer to the form as a "Work Order" but I believe you'll find estimates to be helpful. There are just a few steps to create and send an estimate. Here's how:
1. Click the Create icon (+) in the top right corner.
2. Select Estimate.
3. Enter all of the necessary information.
4. Click Save and send or click the drop-down to choose Save and new or Save and close.