Why I have tax due on my turbotax account but I already paid off my tax?

Do  you mean for 2020?

Why does my TT account say I still owe tax due?

TT does not update after your return has been accepted.  Your account will always show the result of the return you prepared using the software.  TurboTax never knows if you received your refund —or how, when or even if you paid tax due.  Your proof that you paid your tax will be your own bank/credit card records.

ahh I see . Yes 2020 tax return Now I understand. But It’s not gonna affect my tax return for this year 2021?

Your 2020 return does not affect your 2021 return.  Each year is filed independent of the other years, other than a few carryover deductions or credits.