You cannot fix it now. When it goes to the wrong bank account, the bank will send it back to the IRS and then the IRS will issue a check and mail the check to the address on your tax return. Make sure you have the right address on your Form 1040, because that is what they will use.
Here is what the IRS says about entering incorrect banking information
https://www.irs.gov/help-resources/tools-faqs/faqs-for-individuals/frequently-asked-tax-questions-an...
If your refund is sent back to the IRS—- make certain that the address you entered on your Form 1040 is correct. And…open all mail, even if it looks like junk mail.
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**