How do I add money to satisfy IRS withholding requirements?

You can pay from your bank account, debit card or credit card.

Yes. See here. 

https://www.irs.gov/payments/direct-pay

Do you want to pay an Estimated payment?  

Here are the blank Estimates and instructions…..

http://www.irs.gov/pub/irs-pdf/f1040es.pdf

The 1040ES quarterly estimates are due April 18, June 15, Sept 15 and Jan 16, 2024.  Your state will also have their own estimate forms.

Or you can pay directly on the IRS website https://www.irs.gov/payments

Be sure to pick the right kind of payment and year.....2023 Estimate

Q.  How do I add money to satisfy IRS withholding requirements?

A. You make Quarterly Estimated payments.

At the IRS payment site (https://www.irs.gov/payments/direct-pay), select "Estimated Tax" under "Select Reason". 

note that while withholding is assumed to be paid in evenly over the year for 2210 purposes you can use actual withholding for each period. Estimates are deemed paid on the actual date received by the iRS