got it! for anyone interested, Happy Thanksgiving!

     my $response = $browser->request(
        POST $upload_url,
        Content_Type => 'form-data',
        Authorization => 'Bearer ' . $json_auth->{access_token} ,
        Content => [
            'slug'   => 'woohoo',
            'original' => [$image],
        ]
    );
[download]