How to pay a person with Apple Pay

See instructions in Send and receive money with Apple Cash - Apple Support

Be sure that you know and trust the person you are paying. There is no buyer protection and no way to recover the money if the recipient isn't willing to send it back to you. Also see the following from that same support article:

Apple Cash person-to-person payments are like any other private transaction between two people, so only send and receive money with people you know. 

Also make sure you are not purchasing products or services. Using Apple Pay to send money is only for non-commercial purposes. Violating any of the Terms and Conditions could lead to your Apple Cash being terminated permanently.

https://applecash.greendot.com/termsconditions/