my $ct = $pgp->encrypt( Filename => 'plain.txt', Recipients => $key, Cipher => 'DES3', SignKeyID => $signkey, SignPassphrase => $GPG_PP ) or die "Encryption failed: ", $pgp->errstr;
if ($ct) {
    open( my $fh, '>', 'encrypted.gpg' );
    print $fh $ct;
    close $fh;
} else {
    #print "gpg failed: $pgp->errstr\n";
    $err = Crypt::OpenPGP->errstr;
    print "gpg failed: $err\n";
}

##</code><code>##

Data too large for key size at /opt/perl-5.26.0/lib/site_perl/5.26.0/Crypt/OpenPGP/Key/Secret/DSA.pm line 33.

##</code><code>##

    my $dlen = length $dgst;

    my $i = bitsize($key->q) / 8;
    croak "Data too large for key size"
        if $dlen > $i || $dlen > 50;