Were you married in 2019? How did the two of you file? Did you file a joint return? You have to amend it to put your income on it too----preferably before you get a nasty letter from the IRS.
Going forward--remember that ALL of your income must be on the same tax return when you file a joint return. As you are going to find out.....it takes months for the IRS to process an amended return. It is taking about six months right now for the IRS to process amended returns.
It's not clear what you are asking.
1. Did you leave off your income on your 2019 joint tax return ?
2. Or, are you doing your 2020 tax return and don't see a place to enter your income.
If #1, see the reply about filing an amended return for 2019.
If #2, after entering all your wife's W-2 info, you will get a W-2 summary screen. There will be 2 buttons: Add W-2 for (her name) & Add W-2 for (your name)