use feature qw(:5.10);
use strict;
use warnings;

my $str = 'Digits: 123689';

if ($str =~ m{Digits: \s* (?<digits>\d+)}x) {
    my @digits = split //, $+{digits};
    say "Digits: " , join(', ', @digits);
}
else {
    say "No match";
}