If you haven't already filed, you can try the instructions below.
- Click on "Federal Taxes"
- Go to "Wages & Income"
- Click on "edit/add" next to your W2
- Click on "add another W2"
If you received an additional W2 after you had already transmitted (e-filed) your return, to correctly make changes to your return you must amend it.
https://ttlc.intuit.com/replies/5688927
