Apple Pay options will be available in more browsers (not just Safari) on computers.
According to MacRumorsApple Pay will be available in desktop Chrome, Firefox on Mac, and even on Windows PCs. To do this, you will need to scan a special code in the browser using the iPhone camera with iOS 18 and complete the transaction on the phone.
On the desktop, Apple Pay was still limited to Safari on Mac.
This and other changes (including, a lot of AI functions) should arrive on iPhone this fall.