I just filed my 2019 taxes. How do I enter my bank account information to get the stimulus check if I owe money for the 2019 tax season? I did not file in 2018.

Use this IRS website for stimulus payment status or to update your bank account - https://www.irs.gov/coronavirus/get-my-payment

Use this IRS website for get my payment FAQ's - https://www.irs.gov/coronavirus/get-my-payment-frequently-asked-questions

 Check the IRS website for status of the stimulus payment and update your bank information if necessary. it may be a few weeks before your record is available for updating; wouldn't surprise me if the 2019 return has to be processed first, but then again I may be surprised and you can do it now 

  AGI is line 7 on your 2018 return and line 8B on your 2019 return.  Refund is line 21a of the 2019 tax return. and line 20a for 2018

https://www.irs.gov/coronavirus/economic-impact-payments