You will have to mail this in. It can not be efiled.
It depends on what program you are using. See your options here: How do I file an IRS tax extension? - TurboTax Support - Intuit
This will extend the time you have to file your taxes until October 15th, 2025.
Also, you may have to do your state taxes: Do I need to file an extension for my personal state taxes?
Remember, an extension gives you more time to prepare your taxes, but it doesn't extend the time to pay your taxes. If you have an indication that you will owe taxes, you should make the payment by the original due date of the tax return to avoid additional interest and penalties.