You cannot change or add anything on the return that you just e-filed.  It is too late, just like when you put an envelope in a US mailbox

Now you have to wait until the IRS either rejects or accepts your return. If your return is rejected, you will be able to go into your account and make the necessary changes to your tax return and re-submit your return with the right year info. 

If the IRS accepts your return, then you have to wait until it has been fully processed and you have received your refund.  THEN you can prepare an amended tax return 1040X and mail it in. You cannot e-file an amended return.  Meanwhile, DO NOT change anything on your return until you start the amended return.

Only ONE 2019 tax return is filed.  You are supposed to enter ALL income from your W-2's on the 2019 tax return.

If you have e-filed your tax return and need to change the information on the tax return then you will need to wait for the tax return to either be accepted or rejected by the IRS.
If the tax return is rejected then you can make your changes and re-file the tax return.
If the tax return is accepted then you will have to amend the tax return to make your changes. An amended tax, Form 1040X, return can only be printed, signed, dated and mailed by you to the IRS, it cannot be e-filed. The IRS will take up to 4 months to process the amended tax return. Wait until you have received the tax refund or the taxes owed have been paid and processed by the IRS before amending the tax return.