How can I get unbuffered input to a program?

I can't figure out how to get unbuffered input.

I tried:

    method get-selection() {
        getc();
    }

Also tried Term::ReadKey module:

use Term::ReadKey;
    method get-selection() {
        read-key();
    }

But I still have to hit enter before I can capture the input. Couldn't find anything in the docs that might help.

I'm on macOS.