I accidentally hit file before finishing adding dependents

[Texas Roger]

If your return is rejected by the IRS, you can correct the problem and fix the reason for rejection and re-efile your return. If your return is accepted by the IRS, you must prepare, print, sign and mail an amended tax return form 1040X to correct the problem. The 1040X will be available later in February.

DO NOT change your original tax return until you start the amended return. If you have already changed it from the way it was originally filed and accepted, you must change it back before you start the amended return. Wait until you receive the refund from your original return before beginning your amended return to make sure you enter the correct amount. Here is an FAQ to help you:
https://ttlc.intuit.com/questions/1894381-how-to-amend-change-or-correct-a-return-you-already-filed

[Critter]

If you truly went thru all the steps in the FILE tab and clicked on the TRANSMIT now button then  you must now wait until the return is accepted or rejected.

If rejected you can continue entering in information and submit again.