#1 Yes you can pay directly on the IRS website https://www.irs.gov/payments
Be sure to pick the right kind of payment and year.....2025 Estimate
#2 when you file next year you just enter the date you paid and the amount. It is easy. It will be under Federal > Deductions & Credits > Estimates and Other Taxes paid
#4 Turbo Tax will automatically fill out Form 2210 if you have a penalty. If you do have a penalty….you might be able to eliminate it or at least reduce it. You can go to Federal Taxes tab or Personal tab, under Other Tax Situations and select Start by the Underpayment Penalties. You will answer a series of questions that may reduce or eliminate the penalty. Or you can elect to have the IRS figure the penalty for you. It's form 2210.
