Alternatively:

Win8 Strawberry 5.8.9.5 (32)  Fri 02/05/2021 18:49:03
C:\@Work\Perl\monks
>perl -Mstrict -Mwarnings -MData::Dumper

my @data = (
    {
        'sourceL' => 'spacecraft',
        'source' => 'MT',
        'targetL' => 'vaisseau spatial'
        }
    );

print Dumper \@data;

foreach (@data){
    print my $target= ucfirst($_->{targetL});
}

^Z
$VAR1 = [
          {
            'source' => 'MT',
            'sourceL' => 'spacecraft',
            'targetL' => 'vaisseau spatial'
          }
        ];
Vaisseau spatial
[download]

How and from what are you producing the Dumper output (which is what the output looks like)?