To set up person-to-person payments through Messages using Apple Cash, follow the steps below:
Open the Settings app on your compatible iPhone or iPad
Scroll down and tap on Wallet & Apple Pay
Toggle Apple Cash on
Tap Continue and follow the instructions on your screen
Apple
How to set up Apple Cash for a child or teen
It s also possible to set up Apple Cash for a family member that is under 18 and in your Family Sharing group so they too can make purchases, and send and receive money in Messages. You can limit who your child or teen can send money to, get notified when they make transactions, and lock their account.