For 2019? Another W2 for you? Or another person?
If you you already filed and need to add another W2 for you or your spouse for 2019 you need to file a corrected Amended return.
First wait until the first return is fully processed and you got the first refund or paid the tax due.
How to amend a 2019 Online return
https://ttlc.intuit.com/community/amending/help/how-do-i-amend-my-turbotax-online-return/00/27577
You will still get the first refund or need to pay the original tax due. Then the amended return is only for the difference you get back or owe. In fact you should not even amend until the first return has fully processed and you get the first refund or your tax due payment has cleared. And make sure the original refund or tax paid shows up on the amended return. You can confirm this by printing your amendment and looking at the 1040X. Line 18 should be your original refund amount and line 22 should be your additional refund. If you paid on your original return it will be on line 16. If there is an amount owed with the amendment, it will be on line 20.
