401 Unauthorized error about amazon-paapi5-signature HOT 4 CLOSED

    my $sig = Amazon::PAApi5::Signature->new(
        $ACCESS_KEY,
        $SECRET_KEY,
        $payload,
        {
            operation => 'GetItems',
            host      => 'webservices.amazon.com',
            region    => 'us-east-1',
        },
    );
    print Dumper($sig->req_url), "\n";
    print Dumper($sig->headers), "\n";
    print $sig->payload, "\n";

    my $ua = LWP::UserAgent->new;

    my $req = POST $sig->req_url, $sig->headers, Content => $sig->payload;
    my $res = $ua->request($req);

    warn Dumper($res->status_line, $res->content);

`VAR1 = '401 Unauthorized';
$VAR2 = '{"__type":"com.amazon.paapi5#InvalidSignatureException","Errors":[{"Code":"InvalidSignature","Message":"The request has not been correctly signed. If you are using an AWS SDK, requests are signed for you automatically; otherwise, go to https://webservices.amazon.com/paapi5/documentation/sending-request.html#signing."}]}';
`