Send raw transaction (have tx_hex) on litecoin testnet using api or module

I have raw data (tx_hex) for raw transaction, but i cant send it to litecoin tesnet using post request to testnet.litecore.api. If i insert tx_hex manually in the browser, the transaction is correctly sent. My code:

request({
    url: 'https://testnet.litecore.io/tx/send',
    method: 'POST',
    data: test_tx
}, ((error, response, body) => {
    if(error) {
        console.log(error);
    } else {
        console.log(body);
    }
}));

I also tryied to use another service, but it's failing too.

Code :

postdata = { tx_hex : test_tx };
    request.post('https://chain.so/api/v2/send_tx/LTCTEST', postdata, function optionalCallback(err, httpResponse, body) {
        if (err) {
            return console.error('upload failed:', err);
        }
        console.log('Upload successful!  Server responded with:', body);
    });

Someone offers?

Postdata must be String, not Object. ('tx_hex=...')