Please, edit your node and move the question up away from the signature part. Some monks have turned signature display off.

The ?...? delimiter should be written m?...? starting with 5.22.

I'd extend the original code with

use Syntax::Construct qw{ ?? };
[download]

if it were still running in the original environment. But adding the m would work in the old versions, too, so it's an unnecessary step.