What if there is a field with embedded comma (,)?
examples/arrays/process_csv_file_module.csv
Tudor;Vidor;10;Hapci
Szundi;Morgo;7;Szende
Kuka;"Hofeherke; alma";100;Kiralyno
Boszorkany;Herceg;9;Meselo
examples/arrays/process_csv_file_module.pl
#!/usr/bin/perl
use strict;
use warnings;

use Text::CSV;
my $csv = Text::CSV->new({
    sep_char  => ';'
});

my $file = 'process_csv_file_module.csv';
if (defined $ARGV[0]) {
    $file = $ARGV[0];
}
 
my $sum = 0;
open(my $data, '<', $file) or die "Could not open '$file'\n";
while (my $line = <$data>) {
    chomp $line;

    if ($csv->parse($line)) {

        my @fields = $csv->fields();
        $sum += $fields[2];

    } else {
        warn "Line could not be parsed: $line\n";
    }
}
print "$sum\n";