Aside from the fact that getopts is going to try and read from @ARGV and not @_, the usual means of getting keyword-y arguments for subroutines is to use @_ to initialize a hash.

sub blortz {
  my @defaults = qw( foo 1 baz 42 );
  my %args = ( @defaults, @_ );

  print "baz is the answer\n" if $args{baz} == 42;
}

blortz( baz => 2.71828 );
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