If you owe taxes, you have options as to how you will pay the IRS. The easiest and safest way, in my opinion, is to pay online at irs.gov/payments
If you already have an account with IRS, you can login and pay your balance. This method keeps track of your payments and history, plus you can do a lot of other things with your IRS account, so I recommend setting one up eventually if you have not done so yet. They do have a stringent verification process to avoid identity theft so it may take a little time to get this account set up.
If you just want to make a quick payment without the hassle of creating an account, you can do that by clicking on Pay Now with Direct Pay
Make sure you select the correct type and period for the tax your are paying. For example, if you are paying your income tax that was due when you filed your 2023 tax return, you will select "balance due" as your reason for payment, apply payment to "Income Tax - 1040", and the tax period for payment would be 2023. If you are paying tax that was due on an older return, make sure to select the correct year here so it is applied correctly to your account.
To pay Oregon income tax due electronically, go to Revenue Online. It is free to pay with your checking or savings account, but if you choose to pay by credit card, you may be charged a service fee.
If you are one of the lucky folks that are now subject to the Metro Supportive Housing tax or the Multnomah County Preschool for All tax, you can pay those taxes online here https://www.portland.gov/revenue/pay-personal-tax#toc-pay-your-personal-tax-online
If you are not sure if you are in the Metro district and subject to this new tax, you can use this tool to look up your address: https://gis.oregonmetro.gov/metro-boundary-lookup/?_ga=2.264229769.4050046.1641830563-641815136.1601996475#/batch-address-query
Keep copies of screenshots and confirmation numbers showing the payments that you made with your tax records, should you need them in the future.