Put in any payment date in the program if it is needed and when you get to the FILE tab choose to mail in a check ... skip the payment plan section for now. Then send in any amount you can with the payment voucher that prints out and the IRS will bill you for the balance due. If you will pay the balance due off with in a few months then simply send a payment every time the IRS sends a bill. If not go online at www.IRS.gov/payment and set up a payment plan. Also make sure you don't owe again next year by adjusting your withholding if needed now.
Because it is after the July 15 tax deadline, you can’t put any payment date for an automatic bank debit except the day that you file. So you need to select “I will pay by mail“ or “I will pay by check“ or whatever they call it now. The program will let you file your tax return without including a payment, and then you are responsible for making your own payment.
You can make an electronic payment directly to the IRS at www.irs.gov/payments. You can also apply for a payment plan on the IRS website. However, there is a nonrefundable application fee, so if you can pay your taxes in less than 4 months, the interest and penalties will probably be less than the application fee. You can certainly request a payment plan if you need to stretch it out longer than four months.
The most important thing is to file your tax return as soon as you can even if you don’t include payment. The penalty for not filing on time is 5 to 10 times higher than the penalty for not paying on time.