THE IRS CHANGED AMOUNT I CAN APPLY TO 2021 TAX. HOW DO I CHANGE LINE 26 OF 1040SR TO REFLECT REVISED AMOUNT?

make a note to yourself about the new amount and keep it with your important tax documents for inclusion on your return next year.

You might not even file with TurboTax next time.

Wait...do you mean the Federal refund from 2020 was changed, such that the amount that you had applied to 2021 taxes changed too?

IF so, you go to the Federal Deductions&Credits page.

Scroll down the page to "Estimates and Other Taxes Paid"

expand that section

and go into "Income Taxes Paid"

in there you will find an area to go into called "2020 refund applied to 2021 Federal taxes"

that's where you change what was actually applied to 2021 taxes.