fritz@laptop:~/Documents$ ./4.getopt.pl --infile /home/fritz/Desktop/1.tran.txt --outfile /home/fritz/Desktop/1.enc_trans.txt --lang EL --verbose 1
/home/fritz/Desktop/1.tran.txt, /home/fritz/Desktop/1.enc_trans.txt, EL, 1

...
./4.getopt.pl : sending above payload, of 574 bytes...
...
./4.getopt.pl : text=Scylla and Charybdis are the horns of a dilemma.&target_lang=EL
./4.getopt.pl : sending above payload, of 68 bytes..../4.getopt.pl : done, success.
fritz@laptop:~/Documents$ 

##</code><code>##

#!/usr/bin/env perl
use v5.030;    # strictness implied
use warnings;
use utf8;
use Getopt::Long;

#use Net::API::DeepL qw/http_tiny/; # maybe someday...

my ( $infile, $outfile, $lang, $verbose );
$verbose = 0;
if (
  !Getopt::Long::GetOptions(
    'infile=s'  => \$infile,
    'outfile=s' => \$outfile,
    'lang=s'    => \$lang,
    'verbose=i' => \$verbose,
    'help'      => sub {
      print STDERR
        "Usage : $0 --infile xx --outfile xx --lang xx [--verbose N]\n";
      exit(0);
    },
  )
  )
{
  die "error, something wrong with the command-line parameters.";
}

die "parameters needed!" unless $infile and $outfile and $lang;

say "$infile, $outfile, $lang, $verbose";

# at this point consider adding all your parameters into a hash and
# pass that to http_tiny($options) instead of passing a long list which
# may contain optional parameters.
my %h;
$h{infile}  = $infile;
$h{outfile} = $outfile;
$h{lang}    = $lang;
$h{verbose} = $verbose;
my $results = http_tiny( \%h );

die unless $results;

print "$0 : done, success.\n";

sub http_tiny {

  my ($hr) = (shift);

  use Path::Tiny;
  use HTTP::Tiny;
  use JSON::MaybeXS;

  my %h        = %$hr;
  my $file_in  = path( $h{infile} );
  my $file_out = path( $h{outfile} );
  my $lang     = $h{lang};
  my $debug    = $h{verbose};

  # slurp file
  my $guts = $file_in->slurp_utf8;
  my @spl  = split( '\n', $guts );

  # get credentials
  my ( $url, $key ) = get_&#1090;&#1072;&#1081;&#1085;&#1099;&#1081;();

  #say "$url, $key";

  my $ua = HTTP::Tiny->new( 'verify_SSL' => '1' );

  for my $para (@spl) {

    say $para;

    my $payload    = "text=$para&target_lang=$lang";
    my $payloadlen = length($payload);

    my $response = $ua->request(
      'POST' => $url,
      {
        headers => {
          'Authorization'  => "DeepL-Auth-Key $key",
          'Content-Length' => $payloadlen,
          'Accept'         => '*/*',
          'Content-Type'   => 'application/x-www-form-urlencoded',
          'User-Agent'     => 'curl/7.55.1'
        },
        content => $payload,
      },
    );

    die "Failed!\n" unless $response->{success};

    if ( $debug > 0 ) {

      print
        "$0 : $payload\n$0 : sending above payload, of $payloadlen bytes...";
    }

    #print $response->{content} if length $response->{content};
    my $content = $response->{content};

    #say "content is $content";
    my $data = decode_json($content);

    #say "data is $data";
    my $text1 = $data->{'translations'}->[0]->{'text'};
    my $outstring = $para. "\n".$text1."\n";
    $file_out->append_utf8( $outstring);
    

  }
  return $hr;
}

sub get_&#1090;&#1072;&#1081;&#1085;&#1099;&#1081; {

  use Config::Tiny;

  my $ini_path = qw( 1.&#1090;&#1072;&#1081;&#1085;&#1099;&#1081;.txt  );
  my $sub_hash = "deepl";
  my $Config   = Config::Tiny->new;

  $Config = Config::Tiny->read( $ini_path, 'utf8' );

  # -> is optional between brackets
  my $url = $Config->{$sub_hash}{'url'};
  my $key = $Config->{$sub_hash}{'key'};

  return ( $url, $key );
}

__END__