how do i pay someone with apple pay

You pay individuals with AppleCash in-conjunction w/ iMessage.

Send and receive money with Apple Cash - Apple Support

Additionally, no legitimate company requests that you pay using AppleCash via iMessage. (Doing so is a violation of the Terms of Service)

However legitimate companies CAN be paid using AppleCash’s “Virtual Visa” card info.

If the recipe T supports Apple Pay you can pay using your card in wallet by pressing the side button twice

How to send money on Apple pay