Need to make an appointment for today at the Genius Bar to replace my headphones

This is user to user support - you can’t make an appointment with a request here.

Try Genius Bar Reservation and Apple Support Options - Apple.

Slide to the bottom; click on Get Hardware help.

If you’re in an iPhone/iPad, it will probably switch to the support app

Choose the hardware you’re having an issue with (or enter your serial #) and the issue; you should get the option to book an appointment at the Genius Bar.

Can you explain what to click at that link.

All I seem to find are chat and phone.

No appointment reservation function.

The software in my phone is not working