Apple card restricted
Sending and receiving money in Messages has been restricted.
iPhone 11 Pro Max, iOS 15
Question marked as
See: If your Apple Cash account is restricted or locked - Apple Support
or see the following from If you can't send or receive money in Messages with Apple Cash - Apple Support
If you're under 18 years old and part of Apple Cash Family
The family organizer might have locked your Apple Cash account or placed restrictions on who you can send money to in Messages.