seems like turbo set up what i owe in taxes in 4 payments. I want to pay it all on 4/15

The four estimated tax vouchers are for next year (2025).  TurboTax (TT) sees that you did not have tax withheld for 2024 and assumes the same thing will happen in 2025.  So,  it prepares the 2025 vouchers for quarterly estimated payments. It is optional whether you decide to use those. But, you risk an under payment penalty if you don't.

You should pay in quarterly estimated taxes if you don't have enough withholding taken out to cover the tax on all your income. You might be able to increase your W2 withholding, at your regular job, to account for the extra income.
You should make estimated tax payments for the current tax year if both of the following apply:
- 1. You expect to owe at least $1,000 in tax for the current tax year, after subtracting your withholding and credits. 
- 2. You expect your withholding and credits to be less than the smaller of: 90% of the tax to be shown on your current year’s tax return, or  100% of the tax shown on your prior year’s tax return. (110% if your AGI was more than $150K) . Your prior year tax return must cover all 12 months.

TurboTax (TT) can prepare the quarterly payment vouchers. In your 2020 software, enter at:

Federal Taxes or Personal (H&B version)

-Other Tax Situations

  -Other Tax Forms

    -Form W-4 and Estimated Taxes - Click the Start or Update button

On the next screen answer No to the W-4 question

If your goal is just to avoid the underpayment penalty, then paying 100% of the prior year tax liability is the “safe haven”