Does Turbo Tax allow me to deduct a 529 contribution from my state taxes in Illinois?

yes the deduction, if qualified, is taken on scheule M (when you go through the Illinois return) line 13 (2022)

th instructions from schedule M

Step 3: Figure your subtractions for Form IL-1040, Line 7
Enter your subtractions as positive amounts only.
Line 13 — Contributions you made to “Bright Start” College
Savings Pool, “Bright Directions” College Savings Pool, and
“College Illinois” Prepaid Tuition Program.
You may subtract Contributions you made to “Bright Start” College
Savings Pool, “Bright Directions” College Savings Pool, and “College
Illinois” Prepaid Tuition Program. You may also subtract contributions
made on your behalf to one of these plans by your employer. You
may not subtract contributions made to any other college savings
program. If your contributions were made by rolling over funds
from another college savings program into a “Bright Start,” “Bright
Directions,” or “College Illinois” account, you may not subtract any
income that was earned in the other savings program and rolled over
into your Illinois account.
Table 13 - For each row, enter the account number in Column A (do
not enter a name or other information in this column) and amount of
contribution made during the tax year to the “Bright Start” and “Bright
Directions” College Savings Pools and “College Illinois” Prepaid
Tuition Program in Column B. Enter one account per row. Attach
a separate page with any additional accounts, if needed. Add the
amounts in Column B and enter the total on Line 13a.
Check the box in Column C if your contribution was a gift.
If you do not have the account number for a gift
contribution, attach the following:
Copy of the cancelled check used to make the contribution, and
Account holder’s name and address
Enter the lesser amount of Line 13a or $10,000 ($20,000 if married
filing a joint return) on Line 13.
Line 13 may not exceed $10,000 ($20,000 if married filing a
joint return).
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Illinois residents can claim a state income tax deduction for contributions to any of the abobe in-state 529 plans.