I owe a balance. When is the rest due by? It was deferred but I don't know if I will get a bill or reminder. Already filed so I can't pay via turbotax, must I by irs.gov?

For 2020, the payment of your tax due on form 1040 has been extended to May 17, 2021.

You will not receive a reminder from the IRS or TurboTax.

You can pay online using irs.gov/payments