docker is running an internal network, but on droplet gets CORS errors

Hello,

There are no Droplet specific settings. This would happen if the API is running on a different port so that the request origin would not match. Can you share the exact CORS error that you are getting?

You cat add a Access-Control-Allow-Origin to your Node.js app so that it would accept the requests:

app.use(function(req, res, next) {
    res.setHeader('Access-Control-Allow-Origin', '*');
    res.setHeader('Access-Control-Allow-Methods', 'GET, POST, PUT, DELETE');
    res.setHeader('Access-Control-Allow-Headers', 'Content-Type');
    res.setHeader('Access-Control-Allow-Credentials', true);
    next();
});

Let me know how it goes. Best, Bobby