I had to update bank info for the stimulus check and now when I go on to file my personal taxes for 2019 it says I cannot efile them? how do I still efile?

If you used the non filer portal to register for the stimulus payment, you actually efiled a federal form 1040 with $0 income on it. Since a return has already been efiled with your SSN, you will now have to print and mail your return to get it accepted.  Write the words "Amended Return" across the top of the form 1040 to alert the IRS that a previous return was efiled.