Only the TurboTax desktop CD/Download editions have a What-If worksheet in Forms mode that has the 2024 tax rates.
You can use the TurboTax calculator TaxCaster to estimate taxes owed or a tax refund for 2024 (Note that the calculator is for currently for tax year 2023 but should give you a close estimate for 2024) - https://turbotax.intuit.com/tax-tools/calculators/taxcaster/
