How do I send output received from node-pty to res.json() in NodeJS

Question

This is the code I tried to execute using the help of documentation at node-pty and the sample code. I want to send the data received at ls as a response json object.

app.post("/try",(req,res)=>{
    command=req.body.command
    var shell = os.platform() === 'win32' ? 'powershell.exe' : 'bash';
    var ptyProcess = pty.spawn(shell, [], {
    name: 'xterm-color',
    cols: 100,
    rows: 100,
    cwd: process.env.HOME,
    env: process.env
    });
    ptyProcess.onData((data) => {
        res.status(200).json({
            "Status":"Success",
            "Output":data
        })
        process.stdout.write(data);
    });
    ptyProcess.write(`${command}\r`);
    ptyProcess.resize(100, 40);
})

It gives me the following error:

node:_http_outgoing:663
    throw new ERR_HTTP_HEADERS_SENT('set');
    ^

Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client
    at new NodeError (node:internal/errors:399:5)
    at ServerResponse.setHeader (node:_http_outgoing:663:11)
    at ServerResponse.header (/home/sahanaramesh/POC/backend/node_modules/express/lib/response.js:794:10)
    at ServerResponse.send (/home/sahanaramesh/POC/backend/node_modules/express/lib/response.js:174:12)
    at ServerResponse.json (/home/sahanaramesh/POC/backend/node_modules/express/lib/response.js:278:15)
    at /home/sahanaramesh/POC/backend/server.js:48:25
    at EventEmitter2.fire (/home/sahanaramesh/POC/backend/node_modules/node-pty/lib/eventEmitter2.js:40:22)
    at PipeSocket.<anonymous> (/home/sahanaramesh/POC/backend/node_modules/node-pty/lib/terminal.js:85:61)
    at PipeSocket.emit (node:events:513:28)
    at addChunk (node:internal/streams/readable:324:12) {
  code: 'ERR_HTTP_HEADERS_SENT'
}

Node.js v18.14.0
[nodemon] app crashed - waiting for file changes before starting...
[nodemon] restarting due to changes...

I tried to execute a ls command as Express POST request through node-pty. I wanted the resulting data to be sent as a response.json