In IO::Socket::Async§

See primary documentation in context for method print-to

method print-to(IO::Socket::Async:D: Str() $hostInt() $portStr() $str --> Promise)

This is the equivalent of print for UDP sockets that have been created with the udp method, it will try send a UDP message of $str to the specified $host and $port returning a Promise that will be kept when the data is successfully sent or broken if it was unable to send the data. In order to send to a broadcast address the :broadcast flag must have been specified when the socket was created.