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.  

In the meanwhile, DO NOT change anything on your return until you start the amended return.