Can't send json data over WebSocket (NODE JS)

After I created the .onopen event I made it launch some json data over, but I get an error,
Here is the code:

 ws.onopen = ('connect', function(connect) {
            let obj={};
            obj.name='data'
            message = 'connect';
            obj.body=message;
            var data = {"op": 0, "d": {"server_id": serverid, "user_id": author, "session_id": sessionid, "token": tokenn, "video": true, "streams": [
                {"type": "video", "rid": "100", "quality": -1}, {"type": "video", "rid": "50", "quality": 9223372036854775807}]}}, separators=(",", ":");

            ws.send(data.toString())

What I get:
node:events:368
throw er; // Unhandled ‘error’ event
^

Error: read ECONNRESET
at TLSWrap.onStreamRead (node:internal/stream_base_commons:220:20)
Emitted ‘error’ event on WebSocket instance at:

>Solution :

Use "JSON.stringify(data)" for convert Object to string