Thanks. It's great your on Perl v5.36, because that makes function parameters really easy.

First, for backwards-compatibility reasons, you need to tell Perl that you're using the latest syntax. Start your program with:

use v5.36;

However, v5.36 automatically enables strict and warnings for you, so in place of adding the v5.36 line you you can remove those two.†

Then just declare functions like:

sub getNumbers($filename) {

or:

sub sumOverNumbers($file, %scores) {

and Perl will handle the parameters for you.

† Starting your Perl programs with the minimum version number required also means it will check for that and give a sensible error message if somebody attempts to run it on an older version of perl — which is much better than it just failing weirdly on syntax is doesn't recognize. And in forums like this one, it provides documentation for humans, rather than them having to guess which version of perl they need to run.