First of all, while withholding is generally assumed to be paid equally throughout the year, quarterly estimated taxes must be paid equally throughout the year in order to avoid underpayment penalties. You mentioned you paid in 110% of prior year's total tax via withholding, 4th quarter ES and with your extension request. That means you underpaid at least for Quarters 1, 2 & 3, if not all four quarters.
Secondly, you said you still owe $45,000 when you file your tax return. Unless what you have paid in is at least 90% of your total 2022 tax liability, you will incur additional late payment penalties and interests. Extensions only extend the due date of the tax return, not the balance due the IRS. I suggest you file and pay your taxes ASAP to minimize the late payment penalties and interests. If you can't file your tax returns yet, go ahead and pay the $45,000 now. IRS webpay is the fastest and safest way to pay taxes. Go to www.irs.gov.
https://www.irs.gov/pub/irs-pdf/f4868.pdf
Late Payment Penalty
The late payment penalty is usually ½ of 1% of any tax (other than estimated tax) not paid by the regular due date of your return, which is April 18, 2023. It’s charged for each month or part of a month the tax is unpaid. The maximum penalty is 25%.
The late payment penalty won’t be charged if you can show reasonable cause for not paying on time. Attach a statement to your return fully explaining the reason. Don’t attach the statement to Form 4868.
You’re considered to have reasonable cause for the period covered by this automatic extension if both of the following requirements have been met.
1. At least 90% of the total tax on your 2022 return is paid on or before the regular due date of your return through withholding, estimated tax payments, or payments made with Form 4868.
2. The remaining balance is paid with your return.
