Roth Conversion tax payment (cash)

I want to do a Roth Conversion ($88,000) this month and I've already received my 2024 tax refund. I'm 67, not collecting S.S., $15k pension income, after my $17k standard deduction which keeps me in the 22% bracket for the conversion.  My question - how exactly do I properly pay the tax due ($15,312) after opening and funding the Roth to avoid any penalty?  I have cash.  I've read elsewhere that you can simply go to "IRS.gov/payments" and make the estimated payments.  Is this correct?  Do I have to submit any forms as well?