I'll make sure your largest contractor shows up on the 1099 list in QuickBooks Online (QBO).
To start, you'll want to check if your contractor is active and if the Track payments for 1099 option is enabled on the Contractor/Vendor Information.
Here's how to check:
Go to Expenses and choose Vendors.
Locate and select the vendor and click the Edit button.
From the Vendor Information window, see if the box for Track payments for 1099 was checked.
Next, ensure your payments for this contractor meet the threshold since only those you paid above the annual $600 cash threshold will get 1099. Lastly, make sure you're paying contractors from the right expense account.
For future reference, here's a great resource to help you close out your current year and prepare for the new year in QuickBooks with your accountant: Year-end guide for QuickBooks Online.
Fill me in if you have other 1099 concerns or questions. I'll get back to help and make sure you're taken care of.