Unfortunately, once you transmit your return you cannot change it or
get it back. You would have to wait until your return gets rejected or
accepted. 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.
More information regarding amending a return can be found
below:
https://ttlc.intuit.com/replies/3288565