www.irs.gov/payments/direct-pay

"You can easily keep track of your payment by signing up for email notifications about your tax payment, each time you use IRS Direct Pay.

Email notification will contain the confirmation number you receive at the end of a payment transaction.

The IRS continues to remind taxpayers to watch out for email schemes. You will only receive an email from IRS Direct Pay if you’ve requested the service

If you have already made a payment through Direct Pay, you can use your confirmation number to access the Look Up a Payment feature. You can also modify or cancel a scheduled payment until two business days before the payment date.

You can also view your payment history by accessing your online account with the IRS."