First, you will want to wait until your tax return is accepted or rejected. If it is rejected, then you can go in and fix the mistake.
If accepted, then you will want to wait until your original tax return is processed by the IRS. If you are receiving a refund, you should wait until the check is issued. Amended returns must be filed by mail.
If rejected, you can make your changes or add information to your return. If accepted, you would need to amend your return to correct or add information to your return.
If you need to amend your return and you're amending to claim more money, the IRS says to wait until you've received your original refund before filing an amendment. Once you've received your original refund, feel free to cash or spend it while your amendment gets processed (this can take 12–16 weeks). 3 weeks after you mailed your amendment, you can start tracking its progress at the IRS Where's My Amended Return? site.https://www.irs.gov/filing/wheres-my-amended-return
More information regarding amending a return can be found below: https://ttlc.intuit.com/replies/3288565